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Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Introduction:
Tier Two:
Anatomy
Anatomy is the branch of life science concerned with the structure of organisms. Because structure is closely associated with
function at all levels of hierarchy in the life sciences, knowledge of anatomy allows one to understand better how organisms
carry out life's necessary functions such as respiration, metabolism, and reproduction. Physiology, the branch of life science that
deals with the functions of organisms or life processes, complements anatomy, and the two fields are often taught in concert.
Anatomy can focus on the morphology of different types of organisms, such as plant anatomy, vertebrate anatomy, or more
specifically human anatomy. Health care professionals in fields such as medicine, dentistry, and physical and occupational
therapy, and those who work in veterinary medicine, must study human or animal anatomy in order to understand disease and
to help their patients remain healthy. Anatomic anomalies are deviations from normal patterns for a species. For example, while
the normal pattern for a human includes 10 fingers and 10 toes, approximately 0.2 percent of children are born with more, a
condition called polydactyly. Individuals with an extra digit may experience different degrees of affected mobility, but the
condition is not dangerous. Other anatomic anomalies can prevent normal function and cause harm to a patient or may indicate a
serious medical condition. For example, Marfan syndrome results from a mutant gene for the protein fibrillin, a component
necessary for the formation of elastic fibers in connective tissue. One dangerous complication caused by the improperly formed
connective tissue is a leaky mitral or aortic valve in the heart, which can lead to an irregular pulse, shortness of breath, fatigue,
and a potentially fatal aortic aneurism. Individuals with Marfan syndrome have atypically long, slender limbs and fingers, a
symptom that in itself is not harmful in any way. But recognition of this characteristic anatomical feature could aid a physician in
making a timely diagnosis of this disorder.
Even when studies are limited to a particular organism, such as humans, the field of anatomy can be divided into specialties
focusing on a specific region or system or on different levels of organization. Gross anatomy is the study of anatomy on the
macroscopic level, the organs and aspects of the tissues that can be examined without the aid of a microscope. Conversely,
cytology, the study of cellular architecture, and histology, the study of tissues, depend heavily on microscopy. A developmental
anatomist studies the successive changes in body structure as an organism progresses from a fertilized egg to an embryo (a
subspecialty called embryology) and then into a fetus and even into adulthood. In regional anatomy, one focuses on a limited
Columbus City Schools
Academic Vocabulary/
Language
2015-2016
Explain
List
Define
Name
Identify
Tier Three:
superior
inferior
anterior
posterior
medial
lateral
bilateral
ipsilateral
contralateral
proximal
distal
superficial
deep sagittal
transverse
frontal
epigastric region
left and right hypochondriac
regions
umbilical region
left and right lumbar regions
hypogastric region
left and right iliac region
right upper quadrant
1
region such as the head or the abdomen. Systemic anatomy includes study of physiological systems such as the integumentary,
skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, excretory, and reproductive systems.
Comparative anatomy involves the study and comparison of the structures of animal species and often examines the
relationships among different anatomical strategies animals employ for carrying out life processes and the difference in their
environments in which they live or the niches they fill. For example, consider that both aquatic and terrestrial animals require
oxygen to undergo cellular respiration, but the means by which they obtain oxygen gas from their external environment and
transport it to their body tissues differ greatly. Different morphologies have evolved, depending on the needs of that particular
species. The structure of a cell, tissue, organ, or organ system determines the function that structure can accomplish, but over
long periods, different environments select for slightly modified structures that are better suited for those conditions. Thus
structure determines the immediate potential function, but in the long term, the suitability of different functional adaptations
will determine which structures prevail.
One means to study an organism's anatomy is by dissection, the systematic process of separating, taking apart, or exposing the
parts for scientific examination. Teaching laboratories in high schools, universities, and medical colleges rely on dissection as a
means to teach anatomy. Though preserved specimens are still a far cry from living organisms, dissections provide more realistic
anatomical information than learning from observing two-dimensional sketches in a textbook or even three-dimensional images
on a computer.
Anatomic imaging allows physicians to examine internal structures without surgery. X-rays are a form of electromagnetic
radiation with short wavelengths. When an X-ray source is aimed at a region of the body, bones and other dense material in the
path absorb some of the radiation, but it passes through softer tissues and reaches a piece of X-ray film positioned behind the
body part of interest. The X-rays expose the film, and after developing the film, bones will appear white, and the exposed areas of
the film will appear darker, creating a two-dimensional image for a radiologist to examine. Ultrasound imaging produces
sonograms using high-frequency radio waves emitted from a device held next to the skin. The handheld device both transmits
and receives the sound waves, which bounce off internal body structures and are analyzed by a computer. Ultrasound is
frequently used to examine muscles, tendons, and other internal structures as well as to visualize a fetus during pregnancy.
Computed tomography (CT), formerly known as computed axial tomography (CAT), generates a three-dimensional image by
processing a series of subsequent or stacked two-dimensional X-ray images taken at repeated interval angles and reconstructing
a digital image of the internal structures. Another method for obtaining internal structural information, magnetic resonance
imaging (MRI), is better for examining softer tissues than CT scans, as it uses radio frequencies rather than ionizing radiation to
collect data. The patient is placed in a large magnetic field and subject to radio waves, causing the orientation of the numerous
hydrogen protons (mostly from water molecules) to align, a process that occurs at different rates for different types of tissues. A
computer analyzes this information to generate images of cross sections of the body. All of these technologies allow medical
personnel to examine the inside of a patient's body to look for structural abnormalities or even tumors that may be associated
with particular conditions or diagnoses.
right lower quadrant
left upper quadrant
left lower quadrant
cardiology
dermatology
endocrinology
epidemiology
gastroenterology
geriatrics
gerontology
gynecology
hematology
histology
immunology
neonatology
nephrology
neurology
obstetrics
oncology
ophthalmology
orthopedics
otolaryngology
pathology
pediatrics
pharmacology,
podiatry
psychiatry
radiology
toxicology
urology
Cullen, Katherine. "anatomy." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=ELS0007&SingleRecord=True>.
Physiology
Columbus City Schools
2015-2016
2
Physiology is the branch of life science concerned with the function of organisms. Physiologists explore the mechanisms by
which organisms accomplish a task (a mechanistic approach) while considering the purpose or need fulfilled by performing the
function (the teleological approach). A major goal of physiology is to understand how different cells, tissue types, organs, and
organ systems work together to carry out life processes, including homeostasis (the maintenance of relatively stable conditions
inside an organism's body despite external and internal fluctuations), organization, metabolism, growth, adaptation, response to
stimuli, and reproduction. The study of how organisms function is closely tied with their form or structure. The branch of life
science that focuses on the structure of organisms is anatomy, a subject often taught simultaneously with physiology.
Because human physiology is the major discipline related to understanding health and disease, the applications to medicine are
obvious. Knowing how the body works helps to maintain health and to determine the cause when something goes wrong in
order to correct or treat the malady. Health-care professionals, including physicians, nurses, dentists, physical therapists,
occupational therapists, speech and language pathologists, optometrists, chiropractors, pharmacists, athletic trainers, and
others, all receive training in physiology. Veterinarians and agriculturists who raise farm animals or who are involved in animal
husbandry or other animal sciences rely on knowledge of the physiology of the animals with which they work. Studies related to
plant physiology are important for food production and for commercial industries, but also for maintaining healthy ecosystems
and even global climate since plants consume carbon dioxide (a greenhouse gas) during photosynthesis.
Society directly benefits from applications of physiology as a discipline, but biologists also study physiology simply to gain a
better understanding of the living world. Examining the mechanisms by which different organisms, even across kingdoms, carry
out different life processes provides information about evolutionary relationships. In addition to evolutionary biology, the field
of physiology integrates concepts from other branches of life science such as ecology, the study of the interactions of organisms
and their surroundings. The environment in which an organism resides strongly influences how that organism will perform
physiological tasks such as maintaining a stable body temperature or obtaining nutrition. For example, two types of animals,
lynxes and sponges, both must fulfill their nutritional needs by taking in nutrients in the form of presynthesized organic
molecules. Sponges are sessile, marine invertebrates—they live in the ocean, remain attached to rocks or other surfaces, and
feed by filtration. Ocean currents carry plankton (microorganisms such as algae, bacteria, and protozoans that drift with the
currents), which the sponge brings in through pores in its body wall. Specialized collar cells called choanocytes within the
sponge have flagella that whip back and forth to force water through the sponge while trapping the nutritious bits, which are
then picked up by amoebocytes, cells that transport the nutrition throughout the sponge. In contrast, lynxes are predators, and
they must be able to run quickly to chase down prey such as snow hares, for food. Their skeletal systems must be strong and
their musculature must allow for quick bursts of metabolic activity to accompany the powerful movements associated with
running after, capturing, and then tearing apart and chewing their food. Evolution will favor physiological adaptations that
benefit an organism in its quest for food. As evidenced by the predator-prey relationship between lynxes and snow hares,
interactions with other organisms also determines the degree to which a physiological mechanism benefits a species in a
particular environment. Filter-feeding works well for sponges living in the ocean, while this physiological adaptation would
obviously not work for a terrestrial animal such as a lynx.
In addition to integrating other branches of life science such as ecology and evolution, studies in physiology also incorporate
information gained by studying organisms at different levels, from the chemical level up through the level of the organism. Cell
physiology examines the functions occurring at the cellular level. Systemic physiology focuses on one organ system at a time. The
body systems include the circulatory, digestive, respiratory, excretory, skeletal, muscular, integumentary, immune, nervous,
Columbus City Schools
2015-2016
3
endocrine, and reproductive systems. One can also study the physiology of organisms that do not exhibit so many levels of
organization. For example, bacterial physiology aims to elucidate the mechanisms by which bacterial cells carry out all of life's
processes such as growth, maintaining a constant intracellular environment, fulfilling nutritional and energy needs, and
reproduction, despite the fact that the whole organism comprises a single cell.
Cullen, Katherine. "physiology." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=ELS0161&SingleRecord=True>.
I Can Statements
The students can…
Explain how anatomy and physiology are related.
List the levels of organization in the human body and the characteristics of each.
List and describe the major characteristics of life.
List and describe the major requirements of organisms.
Define and explain the importance of homeostasis.
Identify the major body cavities and identify the organs located in each cavity.
Name the major organ systems, list the organs associated with each, and describe the general function of each system.
 Properly use the terms that describe relative positions, body sections, and body regions.







Instructional Strategies and Resources




BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Columbus City Schools
2015-2016
4
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
Columbus City Schools
2015-2016
5
Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Tissuse:
Essential Understandings
In biology, a group of cells that carry out similar and related functions in multicelled animals and plants. The cells of any
particular tissue are basically alike in structure. Organs, such as the heart of an animal or the leaf of a plant, are made up of
several kinds of tissue. The study of tissues is called histology.
Animal Tissues
Most histologists place all animal tissues in four or five general categories. The following is a widely accepted classification.
1. Epithelial Tissue covers the outsides of animal bodies and their organs, and lines the insides of organs and body cavities. It
protects other tissues. Some epithelial tissues, such as the lining of the intestines, absorb nutritious substances into the blood.
Certain epithelial cells (some forming glands) secrete hormones and other substances needed by the body. The outer layer of the
skin is epithelial tissue.
2. Connective Tissue serves mainly to support the body and its organs and to bind other tissues together. The various types
include loose connective tissue (such as ligaments and tendons), cartilage, and bone.
3. Muscular Tissue works with the nerves and bones to provide motion by its characteristic of contracting when stimulated.
4. Nervous Tissue is highly responsive to stimulation and transmits impulses to other tissues.
5. Vascular (or Circulatory) Tissue transports nutrients and other substances through the body, helps maintain normal body
temperatures, and fights infection. It is made up of blood and lymph. Some histologists classify vascular tissue as a type of loose
connective tissue.
"tissue." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=NS170319&SingleRecord=True>.
Columbus City Schools
2015-2016
Academic Vocabulary/
Language
Tier Two:
Describe
Identify
Distinguish
Tier Three:
Prefixes/Suffixes
Adipchondr-cyt
epi-glia
histhyalintermacrneurosphagpseudsquamstratstria-
6
I Can Statements
The students can…
Describe how cells are organized into tissues.
Describe the structure, function and characteristics of epithelial tissue.
Identify, compare and contrast the six different kinds of connective tissue.
Describe and identify the four different kinds of membranes.
Distinguish among the three different kinds of muscle tissue.
 Describe the general characteristics and functions of nervous tissue.





Instructional Strategies and Resources




BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
Columbus City Schools
2015-2016
7
Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Integumentary System:
Academic Vocabulary/
Language
Essential Understandings
An integument is a structure that covers and protects an organism, such as skin on a human, a shell of a diatom, or the husk of a
corn cob. The integumentary system of animals comprises the skin and its accessory organs, including the hair, nails, sweat
glands, and sebaceous (oil) glands. The chief functions of the skin are to cover and protect the body's tissues against water loss
and injury, to prevent the entry of pathogenic microorganisms, and to house sensory receptors that gather information about the
external environment. The accessory organs perform a variety of roles, such as the production of sweat, which helps maintain a
constant body temperature, and the production of certain chemicals such as sebum that prevents the skin from drying out.
Skin
Because it is composed of two or more tissue types and performs a specialized function, the skin is technically an organ. With a
surface area of approximately 20 square feet (almost 2 m2), it is the human body's largest organ. The skin consists of two
distinct layers—the epidermis and the dermis.
The outer layer, the epidermis, is made of stratified squamous epithelial cells. Squamous cells are flat and thin, and stratified
simply means more than one layer exists. The innermost layer of the epidermis contains stem cells (also called basal cells) that
synthesize keratin and melanocytes that produce melanin. Keratin is the substance that makes up calluses and nails, coats hairs,
and forms a tough protective coating over the surface of the skin. The basal cells constantly divide, giving rise to new cells that
push the older cells toward the surface. As they move outward toward the surface of the skin, the cells become keratinized, or
hardened and flattened. Melanin is a pigment that can be yellow, reddish brown, dark brown, or black. The amount of melanin
produced by the melanocytes determines one's skin color. A freckle results from an excess of melanin in one spot. The inner
layer of epidermal tissue also plays a role in the synthesis of vitamin D. The penetration of a small amount of ultraviolet radiation
from sunlight catalyzes the conversion of a molecule derived from cholesterol and found in the lower epidermis into vitamin D.
(The exposure of too much ultraviolet radiation, however, is dangerous because it causes mutations that can lead to skin cancer.)
The outermost layer of epidermis contains 20 to 30 layers of mostly flattened and dead cells that have not yet sloughed off. After
Columbus City Schools
2015-2016
Tier Two:
Define
Describe
Determine
Distinguish
Tier Three:
Prefixes/Suffixes
Alb-,
Cut-,
Derm-,
Epi-,
Folic-,
Hol-,
Kerat-,
Melan-,
Por-,
Seb-,
8
these cells die, their keratin remains, forming a water-resistant, protective covering.
The dermis is much thicker than the epidermis and is composed mainly of fibrous connective tissue containing collagen and
elastic fibers. The hair follicles, sweat glands, sebaceous glands, nerve endings, sensory receptors, and capillaries are all
embedded in the dermis. Capillaries supply nutrients and oxygen to the dermis. The epidermis does not contain its own
capillaries, but small extensions of the dermis that contain capillaries project into the innermost layer of the epidermis to allow
for exchange of nutrients and gases with the metabolically active basal cells. The patterns of these extensions form the whorls
and ridges of fingerprints. Sensory receptors specific for temperature, pressure, and touch detect and relay information about
the external environment to the central nervous system, which processes the information and initiates an appropriate response.
Nerves whose free ends penetrate into dermis act as pain receptors. Skin covering different parts of the body has different
numbers of the specialized types of receptors, causing some areas to be more sensitive to certain kinds of stimuli such as
changes in temperature or degree of pressure. The dermis also contains some adipose tissue, which stores fat, insulates the
body, and cushions against injury.
Below the dermis lies the subcutaneous layer, which technically, is not part of the skin. Consisting mostly of adipose tissue and
some connective tissue, the subcutaneous layer also contains nerves, arteries, and veins that service the skin.
Accessory Organs and Structures
The accessory organs and structures of the skin, including the sweat glands, sebaceous glands, hair follicles, and nails, are all
derived from epidermis. The sweat glands are tubules that lie in the dermis, but extend through the epidermis to an opening at
the skin's surface or sometimes empty into a hair follicle. They function in homeostasis by helping the body maintain a constant
internal body temperature. When the body temperature rises, the sweat glands secrete sweat, which cools the body as it
evaporates on the surface of the skin. As the temperature returns to normal, the sweat glands constrict and become inactive. The
sweat glands also play a minor role in waste excretion by eliminating excess urea and salt with sweat.
Hairs that project from the skin originate at follicles that extend down into the dermis and sometimes into the subcutaneous
layer. Capillary beds associated with the follicles supply nutrients. The sebaceous glands produce and secrete into the follicles an
oily substance called sebum that helps prevent the skin and hair from drying out. During puberty, an increase in steroid
hormone production stimulates the synthesis of excess sebum, which can combine with dead skin cells to clog follicles, causing
blackheads. Bacteria that normally inhabit the skin infect and inflame the blocked follicles, leading to the formation of pimples.
At the base of a hair follicle, epithelial cells multiply, causing the hair to grow outward, and produce keratin, which coats the hair
as it grows. The shape of the hair shaft, the region that projects from the skin, determines whether the hair is straight or wavy,
and melanin made by melanocytes near the follicle determine the hair color. Because melanin production naturally decreases
with age, hair turns gray as one gets older. When someone is frightened or cold, arrector pili muscles associated with each hair
follicle involuntarily contract (goose bumps), causing hairs to stand on end. In animals, raising the hair increases the amount of
air trapped near the skin, an action that insulates the body and prevents heat from escaping.
Human fingernails and toenails are homologous to the claws of birds and reptiles and the hooves of horses and cattle. Composed
of keratinized cells, nails project from a root that is embedded in the skin and covered by a cuticle. Their main function is to
protect the ends of fingers and toes from injury. Just as hair grows when epithelial cells at the base of the follicle multiply, nails
Columbus City Schools
2015-2016
9
grow as cells at the root divide and push the older cells outward.
Cullen, Katherine. "integumentary system." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=ELS0129&SingleRecord=True>.
I Can Statements
The students can…
□
□
□
□
□
Define the term organ.
Describe the structure and function of the skin.
Determine what factors determine skin coloration.
Describe how the skin helps regulate body temperature.
Distinguish between the types of burns, and illustrate the healing process.
Instructional Strategies and Resources




BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Columbus City Schools
2015-2016
10
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
Columbus City Schools
2015-2016
11
Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Skeletal System:
Essential Understandings
The human skeleton is located inside the body tissues, and therefore is called an endoskeleton. Other animals, such as insects
and crustaceans (shellfish), have an exoskeleton—a rigid, tough, outer protective layer that covers their soft tissues.
Exoskeletons, which are found only in some invertebrates, provide strength and a degree of movement, but they have their
limitations. For one thing, the growth of the animal is restricted and happens in phases. After a certain amount of growth, the
exoskeleton becomes constrictive and the organism must molt, or shed, its exoskeleton in order to become larger. During the
molting phase, these animals are particularly vulnerable to damage and to predators. Ultimately, animals with exoskeletons are
limited in size, so there are no animals with exoskeletons among the largest animals on Earth or in its waters. Finally, not all
organisms have skeletons. Bacteria, protozoa, and fungi are mostly microscopic single-celled organisms. Although there are
structures within their cells that serve some of the functions of skeletons, these organisms do not have skeletons in the same
sense as animals. As organisms become more complex and increase in size, they develop the need for a skeleton of some type.
Composition of Bone Tissue
Bone contains both organic and inorganic substances. The organic parts of bone include living cells—the osteoblasts and
osteoclasts; ground substance, which consists of glycoproteins (proteins modified with sugars) and proteoglycans (sugars
modified with amino acids); and collagen. The remainder of bone (about 65%) is composed of inorganic salts, mainly calcium
phosphate. The organic components, particularly the collagen, account for the resilience of bone (its ability to resist breaking
when stressed), while the inorganic components account for its hardness.
Bone is a dynamic structure—it is constantly changing. Osteoblasts are cells that build new bone tissue, while osteoclasts are
cells that break down bone. This allows bone to grow, heal, and adapt to changing conditions.
Structure of Bones
A bone appears, at first glance, to be a solid structure, like a rock. But living bone is actually a complex network of channels and
solid sections (see figure below). A thin section of bone examined under the microscope shows these channels. Each channel has
two parts. The outer portion is a series of concentric rings that form the osteon. The osteon is shaped like a cylinder and runs
parallel to the long axis of the bone. The opening in the center of the osteon is called the Haversian canal. Blood vessels and
nerves pass through the Haversian canals.
Columbus City Schools
2015-2016
Academic Vocabulary/
Language
Tier Two:
Discuss
Classify
Describe
Tier Three:
Prefixes/Suffixes
Acetabulax-blast
canalcarp-clast
clavcondylcoraccribrcristfovgleninterintralamellmeatodontpoie-
12
The structure of the osteon makes bone strong. The layers of the concentric rings consist of long collagen fibers composed of
tough connective tissue. These fibers are arranged in a helix, or spiral, rather than in a straight line. They curve around the
central axis of the canal like a spring. This spiral structure contributes to the strength of the osteon, and is further strengthened
by the fact that each individual layer of the concentric rings spirals in the direction opposite the layers on either side of it. By
alternating the direction of the collagen spirals, the osteon becomes extremely strong. A closer look at the bone section under the
microscope reveals another group of channels that moves away from the Haversian canals at right angles. These are the
Volkmann's (perforating) canals. These canals contain blood vessels and nerves that enter the bone from the periosteum.
The Periosteum
The periosteum is a double membrane that surrounds the outside of a bone (peri means "around" and osteum means "bone").
The membranous coat of the periosteum consists of two layers. The tough, fibrous outermost layer serves as a protective
coating. The inner layer, called the osteogenic layer, is responsible for the growth and reshaping of bones. (Osteo means "bone,"
and genic means "to make or create.") Two basic types of cells are found within this layer: osteoblasts, or bone-building cells,
and osteoclasts, or bone-destroying cells. An easy way to remember these cells is that "osteoBlasts Build," while "osteoClasts
Crunch" (destroy) bones. The periosteum is anchored to the bone itself by bits of collagen called Sharpey's perforating fibers.
The Endosteum
Long bones have a hollow core. This core is lined by another membrane, called the endosteum (endo means "inside" and osteum
means "bone"). This membrane also lines the canals of the bone. Like the periosteum, the endosteum contains osteoblasts and
osteoclasts, which allow bone to grow from the inside as well as the outside.
Functions of Bones
Bones are the foundation on which the rest of the body is built. As a result, they are the first components that define our shape
and form. Bones also serve a number of specific functions that may not be obvious. It is important to remember that not all bones
serve the same function. Each bone is specialized for its location and the job it must perform. Even bones on the right side of the
body are slightly different from the same bones on the left side of the body, as they have mirror-image curvature rather than
identical curvature.
The first basic function for the skeletal system and its bones is support. Bones serve as a framework to which the other organs
and tissues of the body are attached. If you have ever seen a contractor building a house, you may have noticed that the frame is
the first thing to go up after the foundation is laid. It is the framework that supports the house, divides it into rooms, and to
which the outside walls, the inside walls, the floor, the ceiling, and the electrical and plumbing components are attached. The
frame of a house is very sturdy. If constructed properly, the house can withstand tremendous forces and remain intact. So, too,
the framework of your skeleton provides the strength for your body. In order to meet the demands of this function, the bones
must be strong. The bones of the legs must hold the weight of the entire body, and when we run or jump, we increase the force
on the leg bones many times over. The rib cage must hold the weight of the chest away from the lungs and heart so they can
function. The bones of the arms, working with the muscles, allow us to pick up items much heavier than our arms themselves.
These are only a few examples of how the bones provide support.
The second primary function of the bones is protection. Bones act as an armor of sorts. In this case, the armor is covered with a
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layer of skin and muscle, but certain bones are protective nonetheless. The bones of the cranium, a part of the skull, protect the
soft tissue of the brain, the control center for the body. The vertebrae surround and protect the spinal cord, the main
communication cable between the brain and the rest of the body. If either of these organs is damaged, the body either ceases to
function or may be permanently impaired. The rib cage protects the lungs and heart from damage from outside the body, and the
bones of the pelvis cradle the internal organs and, in pregnant women, the developing fetus.
The third function for the bones is movement. Although the muscles are critical for movement, they must have a solid structure
to work against. The ends of skeletal muscles are attached to bones. The bones then act as levers, magnifying the power of the
muscles and allowing specific parts of the body to move. The muscles of the legs would not allow us to walk were they not
attached to the bones of the pelvis, legs, and feet. Likewise, the muscles of our hands and arms would not make ordered and
powerful movements were they not attached to the shoulders, arms, and hands. Even the process of breathing would not be
possible were it not for the spinal column, the ribs, and the sternum. Both the muscles and the bones are essential for the
graceful movements our bodies make.
The fourth function of the bones is the formation of blood cells. Blood cells are formed from special cells in the bone marrow—
the soft center of many bones. In a process called hematopoiesis, these bone marrow stem cells give rise to all of the critical cells
of the blood. Defects in the bone marrow can cause serious problems. For example, if too many white blood cells are produced, a
form of cancer called leukemia results. If not enough red blood cells are made, a condition called anemia results. Not
surprisingly, the activity of the bone marrow stem cells is carefully regulated. Without enough red blood cells, or erythrocytes,
the transport of oxygen from the lungs to the body tissues is decreased, as is the transport of carbon dioxide from the body
tissues to the lungs. Without enough white blood cells, or leukocytes, the immune system cannot protect the body properly. The
synthesis of blood cells is an often overlooked but vital function of the bones of the skeleton.
The fifth function of bones is to serve as a reservoir for minerals. Bones contain high concentrations of the elements calcium and
phosphorus. Both of these elements are essential. Without enough calcium and phosphorus in the diet, the needed minerals will
be removed, or leached, from the bones. This causes the bones to weaken, which can lead to deformity or breakage. You may
have heard that women need more calcium than men. This is generally true because women lose significant amounts of calcium
during menstruation. This calcium must be replaced. As we age, our bodies become less efficient at incorporating calcium and
phosphorus (in the form of phosphate) into the bones, with the result that the bones become weaker and more brittle. Older
individuals are often "stooped"; that is, their shoulders roll forward and their backs curve. This is due to loss of calcium and
phosphate, which weakens the bones, allowing them to deform. Calcium is also essential for muscle strength, and as the muscles
become weaker, the weight of the head tends to tilt the neck and shoulders forward. Exercise is the best way to avoid stooping. It
not only strengthens the muscles, but also promotes incorporation of calcium and phosphate into the bones. You may also have
heard that older people are more likely to fracture their hips. The hips are the center point where the weight of the body is
concentrated. As the bones of the pelvis lose calcium and phosphorus, they become more brittle and are more prone to break.
Hip fractures are particularly difficult to heal because of the constant stress that is applied to the pelvis by the weight of the
body. For this reason, hip fractures are very serious injuries for the elderly, and many older adults never fully recover from a
broken or fractured hip.
The final function of the bones we will discuss is communication. The tiny bones of the inner ear transmit vibrations from the
tympanic membrane, or eardrum, to other structures of the ear, which stimulate nerve impulses that reach the part of the brain
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that processes sound. Without these three tiny bones, we would not be able to hear. Likewise, the skeleton plays an important
role in our ability to speak. A special type of cartilage, the respiratory cartilage, forms the larynx, or voice box, which allows us to
generate the vibrations that eventually become sounds and words.
Types of Bones
The 206 bones of the human body are classified according to their shape. The four major classes of bones are long bones, short
bones, flat bones, and irregular bones
Long bones are much longer than they are wide. The central portion of a long bone, called the shaft, is surrounded by the ends.
The shaft of a bone is also called the diaphysis, and the ends are called the epiphyses (singular, epiphysis). All the bones of the
legs except the kneecaps and ankle bones are long bones, and all the bones of the arms except the wrist bones are long bones.
The name "long bones" can be misleading. Many of the long bones, including those of the hands and feet, are actually quite small.
The term long refers to their relative shape, not their size.
By contrast, short bones, such as those found in the wrist and ankle, are nearly as long as they are wide and thick. This gives the
bones an almost cubelike shape, like the shape of dice. One special group of short bones is the sesamoid bones. These bones
usually have one rounded end and a more pointed end. Their shape is similar to sesame seeds, thus the name "sesamoid." The
patella, or kneecap, is an example of a sesamoid bone.
The third group of bones is the flat bones. Flat bones tend to be wider than they are thick. Flat bones include the sternum, or
breastbone; the scapulae (singular, scapula) or shoulder blades; the ribs—the series of bones that protect the chest cavity; and
most of the skull—the bones that make up the head and jaw.
The final class of bones includes those that do not fit neatly into one of the other three categories. These are called irregular
bones. Among the irregular bones are the hip bones; the vertebrae (singular, vertebra), the bones that form the backbone; and
the bones of the inner ear.
Connections
In this entry we have learned that bones come in a variety of shapes and sizes and that each bone contributes to the function of
the part of the body where it is located. We have learned that bones play a number of roles in the body. They provide a
framework and protection, work with muscles for movement of body parts, produce blood cells, and store minerals. We have
seen that bone is more than a solid, rigid rod. It is a network of canals surrounded by layers of collagen and calcium phosphate.
This network of canals is critical for bone growth and change. We have also seen that bone cells are specialized, including cells
that build up the bone matrix and those that remove it. The action of these cells makes bone dynamic and constantly changing.
Stewart, Gregory J. "bones and other skeletal components of the human body." Science Online. Facts On File, Inc. Web.
18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=HBSMS0002&SingleRecord=True>.
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I Can Statements
The students can…
 Discuss the living tissues found in bone even though bone appears to be inert.
 Classify bones according to their shapes, and name an example from each group.
 Describe the effects of sunlight, nutrition, hormonal secretions, and exercise on bone development and growth.
 Discuss the major functions of bones.
Misconceptions



Bone is not made of tissue.
Bone does not have blood that goes through it.
Bone does not grow
http://theinnerhuman.weebly.com/misconceptions.html
Instructional Strategies and Resources




BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
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Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
Columbus City Schools
2015-2016
17
Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Skeletal System II:
Essential Understandings
Joints
Joints, also called articulations, are where two bones come together. At the junction, cartilage cushions the surfaces of the
opposing bones against pressure and stress from weight bearing and force. A capsule of connective tissue covers the ends of the
bones at the joint and contains synovial fluid, a substance that resembles egg white and functions to lubricate the joint during
movement. Ligaments are the strong bands of tissue that hold bones together and prevent them from moving too far. Animals
can perform a variety of movements due to five different types of joints: ball-and socket, pivot, hinge, gliding, and saddle joints.
Some joints are immovable, such as the sutures in the skull. Others are slightly movable, such as where the bones of the rib cage
meet the sternum or between the vertebrae of the spinal column. The rest are referred to as freely movable or synovial joints,
and their structure determines the degree and type of movement allowed.
Ball-and-socket joints occur in the shoulders, where the humerus meets the shoulder girdle, and the hips, where the femur meets
the pelvic girdle, and enable movement in all directions. The joint where the head meets the top of the spine is an example of a
pivot joint that allows turning or rotation. Hinge joints restrict movement to a single plane, as in the knuckles of the fingers and
toes. Gliding joints allow sliding motions and provide much flexibility when several occur together as in the wrists or ankles.
Rotation, bending, and straightening are all permitted by saddle joints, like at the base of the thumb.
Bone Tissue
During early development, the skeleton of most vertebrates consists of mostly cartilage that serves as a framework upon which
bone is formed by the deposition of minerals. Bone is a living, dynamic tissue that contains living cells, requires a blood supply,
and is innervated, meaning it is supplied with nerves. Osteoblasts, the cells that build bone, first deposit a matrix of the protein
collagen and then secrete calcium, magnesium, and phosphate ions that harden into hydroxyapatite. Because bones are hard,
they confer protection to the internal organs and provide a firm base against which muscles can pull to accomplish movement. A
lesser known function of bone is storage of minerals such as calcium, magnesium, and phosphorus.
Academic Vocabulary/
Language
Tier Two:
Distinguish
Describe
Explain
List
Tier Three:
Prefixes/Suffixes
AnulArthBursCondylFovGlenLabrOvSutureSyndesm-
There are two types of bone tissue: compact and spongy. Approximately 80 percent of the human skeleton consists of the denser
compact bone. At the microscopic level, compact bone consists of units called Haversian or osteonic canals that extend
lengthwise. Surrounded by several layers of mineralized tissue that form concentric rings when viewed in cross section, the
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Haversian canals house the blood vessels and nerves that service the bones. Mature bone cells, osteocytes, are located in the
lacunae, the spaces between the rings. Located inside the outer layer of hard compact bone, spongy bone tissue is more loosely
packed, resembling a honeycomb, and its spaces are filled with bone marrow that stores energy and is the site for blood cell
synthesis. A tough membrane called the periosteum surrounds and protects the bones and contains many blood vessels that
bring nutrients to the bone tissue.
Cullen, Katherine. "musculoskeletal system." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=ELS0153&SingleRecord=True>.
The only functional difference between the male and female skeleton is the construction of the pelvis. The female pelvis is
designed for childbirth, while the male pelvis is not, and it is estimated that if the pelvis is present at a forensic scene, a forensic
anthropologist will be able to tell the sex of the victim with 95 percent accuracy.
The pelvis is made up of the sacrum and two innominate bones, which are also known as the os coxa. Three separate bones, the
ilium, ischium, and pubis form each innominate bone, which fuse during puberty. In general, the male pelvis is narrow and deep,
and the opening in the center, called the pelvic inlet—which is formed by the two pelvic halves—is heart shaped. The female
pelvis is wide and shallow, and the pelvic inlet is oval to allow a baby to pass through during childbirth. On the lower edge of the
ilium, the large fan-shaped bone you feel at your hip, there is a notch called the greater sciatic notch. The angle of the notch is
narrow in males, less than 50 degrees. In females, the angle of the notch is greater than 50 degrees. During a quick check in the
field, a forensic anthropologist can measure the notch with his or her thumb. Place the thumb in the notch: If there is room to
wiggle, it is female, if it is a tight fit, it is male.
At the front of the pelvis, the two innominates meet and form the pubic symphysis. Between them, there is a small piece of
cartilage that cushions the two bones. During pregnancy, a hormone is released that softens the cartilage between the pubic
symphysis so that the two bones actually separate during delivery. After delivery, the cartilage hardens again. Each softening,
separation, and hardening causes pits called scars of parturition to form on the bone. By reading the extent of the scarring on the
symphysis an anthropologist can tell if a woman had given birth or not.
The skull is the second most useful set of bones in the human body when it comes to determining the sex of a skeleton. During
puberty, as the rest of the body is changing, the skull begins to show signs of male- or femaleness. While boys' voices are
changing and their faces are sprouting hair, their facial bones become longer and more prominent. In general, males tend to have
a heavier brow ridge known as the supraorbital ridge over the eyes, and the orbits, or eye sockets, are smaller and square with
rounded edges. Males develop a "Dick Tracy" square chin, or mental protuberance, and a heavy mandible. On the back of the
cranium, males tend to exhibit a large bump on the lower back of the head, which is a muscle attachment line called the occipital
protuberance. On the side of the cranium, males have a larger zygomatic arch and mastoid process. The female skull tends to
keep its gracile form—a smaller cranium, a rounded chin, and less pronounced muscle markings.
When the pelvis and skull are not present, other bones such as the bones of the arm (humerus, ulna, and radius), leg bones
(femur, fibula, and tibia), and even the scapula and patella, or kneecap, can be used to indicate sex, although not as accurately.
Even something as innocuous as the clavicle, or collarbone, can be used to determine a skeleton's sex. Most men have broader
shoulders than women, who can have well-developed arms, legs, and back, but for the most part do not have shoulders as broad
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as a man's because of the clavicle, which acts as a strut pushing the shoulder out to the side. If we did not have a clavicle our
arms would swing into our chests similar to the way a cow's front legs are attached to its body. The clavicle on a male is longer
and extends the shoulder out farther from the body than a woman's shorter clavicle.
Because none of the methods of determining sex from a single bone, including the pelvis, are foolproof, most anthropologists
agree that more than one bone should be used. New techniques are always being devised to get better accuracy, but many times
the technology is too expensive to be practical in a forensic setting. The Y-chromosome fluorescence test detects the presence of
the Y chromosome (the male sex chromosome) in tissue samples that have been stained with quinacrine mustard and viewed
under a fluorescence microscope. The test is very accurate and can determine the sex of remains that have been dead more than
10 years. Unfortunately, it will be a long time before fluorescence microscopes become standard equipment in every police lab.
In the meantime, a forensic anthropologist's skill is less expensive and just as accurate.
Thomas, Peggy. "idenitfying basic features from skeletal remains." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=STFA0008&SingleRecord=True>.
I Can Statements
The students can…
□
□
□
□
□
Distinguish between the axial and appendicular skeletons, and name the major parts of each.
Describe the differences between male and female skeletons.
List the functions of joints.
Describe how bones of cartilaginous joints are held together. Describe the general structure of a synovial joint.
Explain how skeletal muscles produce movements at joints, and identify several types of joint movements
Misconceptions
 Bone is not made of tissue.
 Bone does not have blood that goes through it.
 Bone does not grow
http://theinnerhuman.weebly.com/misconceptions.html
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Instructional Strategies and Resources




BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
Columbus City Schools
2015-2016
21
Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Muscular System:
Models of the atom, ions, Isotopes
Essential Understandings
Skeletal muscles work in opposing pairs to move the skeleton and, therefore, the body. Thus, the first function of the muscles is
to carry out voluntary movement, movement that is under conscious control. Skeletal muscles also function in stabilization of the
body. Although the skeleton provides rigid support for the body, the muscles, by balancing the pull of opposing pairs, act to
stabilize the bones and therefore hold the body in place. Our posture is dependent on the stabilizing effect of the muscles.
Attachment of muscles to vital organs helps to hold those organs in place. A visual analogy is the Golden Gate Bridge in San
Francisco, California, a classic example of a suspension bridge. Massive cables connect the main platform of the bridge to the
metal structure that suspends it. These cables stabilize the platform to the frame, much as the muscles stabilize the bones of the
skeleton and the vital organs to the bones or other tissues.
Among the voluntary movements involving skeletal muscles are those involved in communication. The muscles of the face,
especially those of the jaw and tongue, are incredibly complex. The intricate control and movement of these muscles, along with
those of the larynx, or voice box, allow us to make the multitude of sounds that lead to verbal communication. People who are
mute (unable to speak) can also communicate through sign language by using the muscles of the hands and arms to create
equally intricate and subtle movements. Without our muscular system, human communication as we know it would not be
possible.
Skeletal muscles also function in the generation of heat. Muscle cells burn large amounts of glucose, a simple sugar that is the
primary fuel for the cells of our bodies. The energy from the chemical breakdown of glucose is used to produce ATP, which in
turn provides the energy for muscle movement. Heat is generated as a by-product. This is why you become overheated from
intense or prolonged exercise. Your skeletal muscles are generating more heat than the body needs to maintain its normal
temperature. Under conditions of extreme cold, the voluntary muscles undergo an involuntary process called shivering, where
the muscles undergo uncontrolled spasms. The body triggers shivering if the temperature of the trunk of the body begins to
drop. Shivering generates heat and helps to maintain normal body temperature.
Academic Vocabulary/
Language
Tier Two:
List
Describe
Explain
Distinguish
Compare
Tier Three:
Prefixes/Suffixes
CalatErgFasc-gram
HyperInterIsoLatenMyoReticulSarcoSynTetan-tonic
-troph
Voluntar-
General Muscle Anatomy
Muscles come in a variety of shapes and perform a variety of functions. As a general rule, most skeletal muscles attach to bones
or other structures at two sites. One attachment site is relatively immobile, while the other attachment site is much more mobile.
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The relatively immobile, or stationary, end of a muscle is called the origin, while the more mobile end of the same muscle is
known as the insertion. Many muscles tend to be wider in the middle and taper toward the origin and the insertion. This
thickened middle area is called the belly.
The more than 600 muscles of the human body can be divided into 5 groups based on the arrangement of the bundles of muscle
fibers. The groups are fusiform, parallel, convergent, pennate, and circular muscles
Fusiform muscles are spindle-shaped—tapered on the ends and thicker in the middle. Since this design concentrates the
strength of a large bundle of muscles at relatively small origins and insertions, fusiform muscles tend to be strong. The biceps
muscle of the upper arm is a fusiform muscle.
Parallel Muscles
As the name suggests, parallel muscles have bundles of fascicles that are essentially equally wide at the origin, the insertion, and
the belly. These muscles form belt-like structures. In the relaxed state, parallel muscles can be quite long. Although they can
shorten more than fusiform muscles, relative to their relaxed length, they tend to be less strong than fusiform muscles. The
muscles of the abdomen are parallel muscles.
Convergent Muscles
Convergent muscles are shaped like a fan. They are wide at the origin and narrow at the insertion. The strength of a large
number of fascicles concentrated at the insertion makes convergent muscles quite strong. The pectoralis major muscle of the
chest is a convergent muscle.
Pennate Muscles
Pennate muscles are shaped like feathers. The bundles of muscle fibers insert onto a tendon that runs the length of the muscle.
Pinnate muscles can be further divided into three groups. Unipennate muscles are those in which the fascicles all attach from the
same side. The palmar interosseous muscle in the palm is a unipennate muscle. Bipennate muscles have bundles of muscle fibers
that attach to the tendon from two sides with the tendon in the middle. The rectus femoris muscle of the thigh is a bipennate
muscle. Multipennate muscles are shaped like several feathers that have all their quills joining at a single point. An example of a
multipennate muscle is the deltoid muscle of the shoulder.
Circular (Sphincter) Muscles
Circular, or sphincter, muscles form rings around various openings in the body. The muscles around the lips and the eyelids are
circular muscles.
Working in Groups
Body movements usually do not involve the action of a single muscle alone. More often, groups of muscles coordinate their
actions to provide a smooth, even movement. As a general rule, the muscles that work together as a functional group fall into
four major categories.
Agonist Muscles
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The muscle that exerts the majority of force in a movement is known as the agonist, or primary mover. When you bend your
elbow, the biceps muscle is the agonist.
Synergist Muscles
Most agonist muscles have other muscles that aid their motion. Muscles that work additively to the agonist are known as
synergist muscles. In addition to adding strength to the agonist, the synergist helps to stabilize the movement or to restrict the
range of movement of the agonist.
Antagonist Muscles
Since muscles can only pull, not push, to reverse the action of the agonist, a complementary muscle or group of muscles must
work in the opposite direction. An antagonist muscle works in opposition to the agonist. In addition to returning the body part to
the original position, antagonists fine-tune the control of the agonist. They moderate the speed and the range of the agonist,
which helps to protect the body from damage to muscles or joints. The triceps muscle along the back of the upper arm is the
antagonist to the biceps. It is important to remember that while the biceps is the agonist and the triceps is the antagonist when
the elbow is bent, their roles reverse when the elbow is straightened—that is, the triceps becomes the agonist and the biceps the
antagonist.
Fixator Muscles
Fixator muscles are those that prevent a bone from moving in an unwanted direction. For instance, when you want to bend your
elbow, the biceps muscle does the most of the work. The biceps connects to the shoulder blade, or scapula, at its origin and on
the radius at its insertion. Fixator muscles attached to the scapula prevent it from moving when the biceps contracts to ensure
that the energy of the biceps is concentrated on moving the radius, not the shoulder blade.
Muscles of the Face
Generally, the muscles of the face are small and short to allow tremendous precision and control, but not a significant amount of
strength. The exceptions to this rule are the muscles of the jaw, which are extremely strong. Facial muscles control facial
expression, chewing, swallowing, and, in part, speech.
Muscles of Facial Expression
The muscles that control facial expression are much more highly developed in primates than they are in other animals. The
mouth is the most sensitive structure of facial expression. It is surrounded by a circular muscle responsible for closing the lips. A
similar circular muscle surrounds each eye and allows the eyelids to close. The other muscles of the mouth radiate outward from
the mouth like spokes on a wheel. The origins of the muscles tend to be away from the mouth, while the insertions are attached
to the skin rather than to bone. This combination of specialized structures and anchoring to soft tissue allows for countless and
subtle facial expressions, from smiles to frowns to pouts.
Chewing and Swallowing
The tongue is one of the strongest and most flexible structures in the human body. It has sets of muscles originating and
terminating within the tongue (intrinsic muscles), and muscles that connect the tongue to other parts of the neck and head
(external muscles). The tongue plays a vital role in digestion, as it, along with the muscles of the cheeks, moves food around the
mouth. The tongue also delivers the chewed food to the back of the throat, where it enters the esophagus.
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The action of chewing is controlled by four paired muscles of mastication, or the act of biting and grinding food in your mouth.
Two of these that attach at or near the mandible are among the strongest muscles of the body. They allow us to bite and to chew
our food. The other two pairs of chewing muscles are important in moving the mandible from side to side for the grinding of food
by the molars. Also important for chewing and swallowing are eight pairs of hyoid muscles, which are muscles associated with
the hyoid bone, a U-shaped bone at the base of the tongue that supports the muscles.
As food enters the pharynx, the back of the throat, three pairs of muscles known as the pharyngeal constrictors contract and
force the food down the esophagus.
The larynx also has intrinsic muscles that control the vocal cords, and thus are essential for speech. These muscles also control
the opening of the larynx itself to prevent food or fluids from entering the trachea.
Muscles That Control the Head
The bones of the skull are very heavy. Consequently, the muscles that control and support the head must be very strong. There
are two major groups of muscles for the head: flexors and extensors. All muscles in these groups have their inserts on cranial
bones and their origins on the vertebrae, the thoracic cage, or the pectoral girdle. The flexors draw the head downward toward
the body. These muscles are generally located along the sides of the neck. The extensors extend the neck and rotate the head.
The extensor muscles are located at the back of the neck. In general, flexors act to decrease the angle at a joint, while extensors
increase the angle at a joint. For example, the biceps muscle is a flexor of the lower arm, while the triceps, the muscle on the back
of the upper arm, is an extensor.
Muscles of the Trunk
The muscles of the trunk include the muscles of the abdomen, the muscles of the back, and the muscles of respiration.
Muscles of the Abdomen
The abdominal muscles consist of four pairs of muscles that form strong sheets. These muscles serve a number of functions.
First, they work with the back muscles to hold the body upright and support the weight of the chest cage, arms, and head.
Second, they support and protect the spinal column. Third, they hold and support the internal organs. Fourth, they assist with
the vital functions of breathing, waste removal, and reproduction.
The role of protecting organs is vital because, unlike the lungs and heart, which are surrounded by a bony cage, the organs of the
abdomen are not protected by hard bone. Thus, the abdominal muscles must be strong in order to insulate and protect the
organs—the stomach, liver, spleen, and intestines—that are located in the abdominal cavity.
Muscles of the Back
The muscles of your back also serve a number of functions. They work as antagonists to the abdominal muscles to help control
the movement of bending forward. They enable the body to return to an erect posture after bending at the waist. They also work
together with the abdominal muscles to maintain an upright posture. Back muscles fall into two groups. Superficial muscles of
the back connect the ribs to the vertebrae, while the deep muscles of the back connect the vertebrae to one another.
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The primary mover of the back and spine is the erector spinae. This is the bundle of muscles and tendons that causes you to
straighten after you bend at the waist. This muscle group can be divided into three sections: the iliocostalis group, which assists
with breathing by driving inhalation; the spinalis group; and the longissimus group. All three groups assist with extension or
flexing of the vertebrae. The muscles of the longissimus group are concentrated in the lower back, while the other two groups
are concentrated in the mid to upper back.
Muscles of Respiration
Three basic muscle groups drive the respiration process. The diaphragm is a sheet of muscle that defines the bottom of the chest
cavity and separates it from the abdominal cavity. In addition to the diaphragm, there are 11 pairs of external intercostal
muscles, located between the ribs and just below the skin, and 11 pairs of internal intercostal muscles, also located between the
ribs, but below the layer of the external intercostals. You may be surprised to learn that the lungs themselves do not contain
skeletal muscles. The role of the lungs in the inhalation and exhalation process is purely passive.
In inspiration (breathing in), the diaphragm contracts, causing it to flatten and to lower slightly, and the external intercostals
contract, lifting the ribs up and away from the lungs. Altogether, the actions of the external intercostals and the diaphragm
enlarge the chest cavity, creating a vacuum and pulling on the tissue of the lungs. The lungs, which are flexible in a healthy
human, stretch, opening the air sacs within, and air rushes in from the mouth and nose to fill the space.
When the muscles of the diaphragm and external intercostals relax, the weight of the chest cage causes the chest cavity to
collapse inward, passively forcing out the air in the lungs. The role of the internal intercostal muscles is in forcible exhalation.
For example, if you want to blow up a balloon, simply relaxing the diaphragm and the external intercostals will not provide
enough force. The needed force comes from the internal intercostals, which contract, pulling the ribs toward each other and
toward the lungs. This forces air out of the lungs and creates the air pressure you need to inflate that balloon or to blow out
candles at a birthday party.
Connections
In this entry, we have explored the general anatomy of muscles. We have seen how muscles work in groups to create smooth,
fluid motions and how some muscles are designed for strength, while others are designed for delicate, accurate movements. We
have learned that while many muscles connect to bone, others can connect to softer tissues to allow for subtle movements. We
have learned that muscles usually work in opposing pairs and that these pairs not only can reverse the action of the opposite
muscle group, but can also control the intensity of a movement. We have learned that some muscles are used to stabilize the
movements of bone and other muscles, thus creating smooth, graceful movements.
Whether they are used for power, as one observes in a weightlifter, or grace, as one observes in a ballet dancer, the skeletal
muscles allow us to move our body in an almost endless range of motions.
Stewart, Gregory J. "skeletal muscles." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=HBSMS0008&SingleRecord=True>.
Cardiac Muscle
Cardiac Muscle, or Involuntary Striated Muscle, is found only in the walls of the heart. Its fibers, like those of skeletal muscle, are
Columbus City Schools
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cylindrical and striated, have many nuclei, and are arranged in bundles. The fibers branch at the ends, and the branches of
neighboring fibers interconnect, making it difficult to tell where one fiber ends and another begins. Heart muscle is under the
control of the autonomic nervous system, and contracts rhythmically and automatically.
Smooth Muscle
Smooth Muscle, like heart muscle, is not consciously controlled. It is found chiefly in the internal organs. Its action is regulated by
the autonomic nervous system and by hormones. Smooth-muscle fibers are spindle-shaped and each has one nucleus. The fibers
are arranged in bundles, sheets, or layers. They form the walls of the blood vessels, stomach, and intestines. Some smooth muscle
fibers occur singly. An example is the arrector pili, a muscle fiber in mammals that is attached to a hair follicle. If the mammal is
cold or frightened, the muscle fiber contracts, causing the hair to stand erect.
"muscle." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=NS111029&SingleRecord=True>.
I Can Statements
The students can…
List various outcomes of muscle actions.
Describe and name the major parts of a skeletal muscle fiber and describe the functions of each.
Describe and identify the major events of skeletal fiber contraction.
Explain how various types of muscular contractions produce body movement and help maintain posture.
Distinguish between fast and slow twitch muscle fibers
Compare the contraction mechanism of skeletal and smooth muscle fibers.
 Compare the contraction mechanism of skeletal and cardiac muscle fibers.






Misconceptions


Muscles don't have layers, works as one major unit.
Muscles control themselves (but only rarely do they).
http://theinnerhuman.weebly.com/misconceptions.html
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Instructional Strategies and Resources




BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
Columbus City Schools
2015-2016
28
Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Muscular System II:
Academic Vocabulary/
Language
Tier Two:
Essential Understandings
Skeletal Muscle, or Voluntary Striated Muscle, is under conscious control. It is found in all the muscles attached to the skeleton,
and in the muscles of the tongue, esophagus, and pharynx. It moves the bones and helps maintain posture. The muscle is called
striated because the fibers have alternating light and dark bands, visible through a microscope. The light bands are thin and
contain the protein actin; the dark bands are thick and contain the protein myosin. Each fiber is a thin, elongated cylinder with
rounded ends and contains many nuclei. It is enclosed in a sarcolemma, a thin elastic sheath of membrane. The fibers are held
together in bundles by connective tissue, and several bundles form a muscle.
There are two types of skeletal muscle fibers: fast-twitch fibers and slow-twitch fibers. Fast-twitch fibers contract rapidly and
with great force; some fast-twitch fibers fatigue rapidly, while others fatigue at a moderate rate. Slow-twitch fibers contract
slowly and with less force than fast-twitch fibers, and fatigue slowly. Most persons have approximately equal amounts of the two
types of fibers. This is often not true of athletes, however; sprinters, for example, tend to have a high percentage of fast-twitch
fibers and distance runners a high percentage of slow-twitch fibers.
Some skeletal muscles are enclosed in a sheath of connective tissue that extends beyond the muscle fibers at each end. These
tissues, called tendons, attach the muscle to a bone. The origin is the end of a skeletal muscle that is attached to a bone that it
does not move. The insertion is the end attached to a bone moved by the muscle. Some muscles branch at the ends and have
more than one origin or insertion. For example, the biceps brachii, the muscle that flexes the forearm, has two origins on the
scapula (shoulder blade) and one insertion on the radius, a bone of the forearm.
"muscle." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=NS111029&SingleRecord=True>.
Columbus City Schools
2015-2016
Explain
Identify
Describe
Tier Three:
Prefixes/Suffixes
CalatErgFasc-gram
HyperInterIsoLatenMyoReticulSarcoSynTetan-tonic
-troph
Voluntar
29
I Can Statements
The students can…
□
□
□
Explain how the attachments, locations, and interactions of skeletal muscle make possible certain movements.
Identify and locate the skeletal muscles of each body region and describe the action(s) of each muscle.
Describe the muscular changes associated with life span changes.
Misconceptions


Muscles don't have layers, works as one major unit.
Muscles control themselves (but only rarely do they).
Instructional Strategies and Resources




BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Columbus City Schools
2015-2016
30
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
Columbus City Schools
2015-2016
31
Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Nervous System:
Academic Vocabulary/
Language
Essential Understandings
In most kinds of animals, the body's system of communications. It is made up of special cells, tissues, and organs that transmit
messages in the form of nerve impulses. Some of the impulses help control and coordinate the activities of organs within the
body; nerve impulses, for example, keep the heart beating. Others, such as those triggered by heat or cold, cause an awareness of
changes in the body's surroundings.
The major part of this article is concerned with the human nervous system.
Cells and Organs of the Nervous System
The basic functional unit of the nervous system is the nerve cell, or neuron. A neuron is made up of the cyton, or nerve cell body
including the nucleus, and two kinds of nerve fibers: dendrites and axons. The spaces around neurons are occupied by glial cells.
They provide structural support for the neurons and help regulate the metabolism of the neurons. The junction of one neuron
with an adjoining related neuron is called a synapse. Synapses usually occur between the axon of one neuron and the dendrites
of another. However, a synapse can occur between two axons or two dendrites, or between the axon of one neuron and the cell
body of another. A typical neuron has 1,000 to 10,000 synapses. It receives information from 1,000 other neurons.
The human body contains billions of neurons. They are found in the brain, spinal cord, and peripheral ganglia (groups of nerve
cell bodies located outside the brain and spinal cord; the singular is ganglion). No two neurons are identical in form; the
numerous kinds of neurons differ widely in size and shape. Many have globe-shaped or pyramid-shaped cell bodies; short,
branching dendrites; and single, long axons that branch only at the ends.
A nerve fiber may be enclosed in one or two kinds of sheaths. Some fibers are surrounded only by a sheath of white, fatty
material called myelin. Others also have a neurilemma—a transparent membrane—outside the myelin sheath. It is composed of
glial cells known as Schwann cells, which are necessary for nerve regeneration. Some fibers are enclosed only in a neurilemma.
Some have neither covering. The nodes of Ranvier are interruptions in the myelin sheath that occur at regular intervals along the
axons. They conduct impulses faster than nonmyelinated fibers because impulses jump from node to node rather than passing
continuously along the fiber.
Columbus City Schools
2015-2016
Tier Two:
State
Identify
Describe
List
Compare
Tier Three:
Prefixes/Suffixes
AstrAxBiDendrEpendym
-lemm
MotoMultiOligoPeriSaltatorSensSynUni-
32
A nerve is a bundle of nerve fibers from many neurons held together by connective tissue. A plexus is a nerve center composed of
grouped and interconnected ganglia. A nucleus is a group of nerve cell bodies found inside the brain or spinal cord. (The term
nucleus, as previously mentioned, also refers to a component of individual cells.)
Neurons may be classified by the direction in which they carry nerve impulses. Afferent, or sensory, neurons carry nerve
impulses to the brain or spinal cord. A stimulus may initiate the impulses directly in an afferent neuron. The body also has many
sensitive cells called receptors that react easily to stimuli and initiate impulses in the afferent neurons with which they are in
contact.
Association, or adjustor, neurons in the spinal cord or brain transmit the nerve impulses from afferent neurons to efferent, or
motor, neurons. The efferent neurons carry the impulses to effectors, the muscles or glands that carry out appropriate
responses. A nerve may be made up of only afferent or only efferent neurons, or of a mixture of both.
Nerve Impulses
A nerve impulse is a special and complicated kind of electrical activity that is associated with and dependent upon chemical
changes. The changes are relayed by neurotransmitters, chemical substances stored in tiny sacs (synaptic vesicles) in the axons.
The arrival of the nerve impulse at the axon causes the discharge of large numbers of neurotransmitter molecules into the
synapse. The neurotransmitter molecules diffuse across the gap and interact with specific receptors on the membranes of the
dendrites. This interaction changes the electrical activity of the neuron, causing it to become excited. As a result either a muscle
cell contracts or a gland cell manufactures and secretes a hormone. The time for the reaction to occur varies from one second to
several hours. The behavioral effects of many drugs and neurotoxins have been linked with their ability to disrupt or modify
neurotransmitters.
Human nerve impulses travel at a speed of 3 to 300 feet (90 cm to 90 m) per second. The speed and strength of the impulse
remain the same all along the nerve fibers, and are not influenced by the intensity of the stimulus that started the impulse.
However, strong or repeated stimuli affect more fibers and also increase the frequency of the impulses, thereby resulting in a
stronger response by the effector.
As a nerve impulse passes along a neuron, changes take place in the neuron, and it is said to be depolarised. A wave of
repolarization follows the impulse. The period in which the neuron is depolarized lasts a few thousandths of a second. During
this refractory period no other nerve impulse can travel along the neuron.
Divisions of the Nervous System
There are two main divisions of the nervous system: (1) the central nervous system, and (2) the peripheral nervous system.
They are connected and work together.
The Central Nervous System consists of the brain and the spinal cord. Most nerve impulses are relayed to the brain. It is the seat
of consciousness and the higher mental functions, and is the control center for most bodily functions.
The spinal cord is a slightly flattened tube that is continuous with the brain and runs through most of the spinal column, or
backbone. An adult person's spinal cord is about 18 inches (45 cm) long. A small central canal extends through the center of the
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spinal cord. This canal is surrounded by gray mater, composed of the ends of axons of afferent neurons, entire association
neurons, and the dendrites and cell bodies of efferent neurons. Around the gray matter is white matter, composed largely of the
eliminated fibers of afferent and efferent neurons.
In addition to neurons, the spinal cord is made up of cells called neuroglia, which support the neurons. The spinal cord, like the
brain, is enclosed in three layers of connective tissue called the meninges. The inner layer is the pia mater, the middle layer is the
arachnoid membrane, and the outer layer is the dura mater. Cerebrospinal fluid circulates between the membrane and the mater
to help moisten and protect the tissues. This fluid is also found in the central canal and other parts of the central nervous system.
The Peripheral Nervous System is made up of pairs of nerves that connect the central nervous system to the other parts of the
body. Twelve pairs of cranial nerves arise from the brain and connect it with the sense organs and muscles of the head, and with
the viscera—such internal organs as the heart, lungs, stomach, and intestines. Thirty-one pairs of spinal nerves arise from the
spinal cord and connect to the skin, and to other muscles and sense organs in the trunk and limbs.
Each spinal nerve is connected to the spinal cord in the back by a dorsal root and in front by a ventral root. The dorsal root
contains the cell bodies and part of the fibers of afferent neurons. The ventral root contains part of the axons of efferent neurons.
Each spinal nerve proper is composed of the dendrites of afferent neurons and the axons of efferent neurons. (The cell bodies of
the efferent neurons are located in the gray matter of the spinal cord.)
Certain neurons of the peripheral system make up the autonomic nervous system. These neurons control muscles of the viscera
and blood vessels, certain muscles of the skin and eyes, and certain glands. The autonomic nervous system functions
involuntarily, and is not generally under conscious control. Some of its neurons differ from other peripheral neurons in that they
do not extend directly from the central nervous system to the effectors. One set of efferent neurons extends from the central
nervous system to a ganglion belonging to a second set of efferent neurons which extends to the effectors.
The autonomic nervous system is divided into a sympathetic system and a parasympathetic system. Both systems usually
activate the same effectors, but carry impulses from different parts of the central nervous system. The two systems have—in
general—opposite effects on the organs, thus keeping the internal functions of the body in a state of balance. (Such a state of
balance, or equilibrium, in the internal environment of the body is referred to as homeostasis.)
Under conditions of stress, however, when the body's equilibrium must be temporarily set aside to meet a crisis, it is the
sympathetic system that has the greater effect on the body. For example, the sympathetic system stimulates the production of
the large amounts of epinephrine needed when a person requires a burst of energy to meet an emergency.
Disorders of the Nervous System
Diseases and defects of the nervous system are probably the leading cause of disablement. Nervous defects may be hereditary or
may be caused by injuries occurring before or at birth. Nervous disorders may be caused later in life by injuries, infectious
diseases, tumors, alcoholism and other addictions, vitamin deficiencies, and circulatory disorders such as arteriosclerosis.
Many nervous disorders are especially severe because the nerve tissue of the central nervous system cannot regenerate once it is
destroyed. Peripheral nerve tissue may regenerate under certain circumstances, but it takes longer to recover normal
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34
functioning than do other body tissues.
Many types of mental illness are classified as functional, because there is no observable damage to the nervous system. However,
such illness is usually considered to be of nervous origin.
"nervous system." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=NS120118&SingleRecord=True>.
I Can Statements
The students can…
□
□
□
□
□
□
□
□
□
□
Columbus City Schools
State the general functions of the nervous system.
Identify two major types of cells that comprise the nervous tissue.
Identify two major groups of nervous system organs.
Describe how the nervous system responds to stimuli.
List the functions of the sensory receptors.
Describe the parts of the neuron.
Describe Schwann cells in the peripheral nervous system.
Describe the events leading to the conduction of a nerve impulse.
Compare nerve impulse conduction in a myelinated and unmyelinated neuron.
Describe the basic ways in which the nervous system processes information
2015-2016
35
Instructional Strategies and Resources




BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
Columbus City Schools
2015-2016
36
Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Nervous System II:
Essential Understandings
The part of the nervous system that is enclosed in the skull. All vertebrates (animals with backbones) have well-developed
brains; most invertebrates (animals without backbones) do not have true brains. Instead, they have groups of nerve cells called
nerve nets, nerve cords, or ganglia. This article is concerned almost entirely with the human brain.
Academic Vocabulary/
Language
The human brain is an extension of the spinal cord, and with it makes up the central nervous system. It contains billions of
neurons, or nerve cells, each with more than 10,000 synapses, or connections to other neurons. No two brain cells are alike. The
brain cannot regenerate new brain cells but it can bypass dead or damaged cells to form new synapses between existing cells.
Describe
Discuss
Explain
Distingush
Idenitify
The brain receives information from all parts of the body and sends out instructions to the body's various organs and systems.
The information and instructions travel through the brain in the form of nerve impulses, electrical signals that elicit chemical
changes. The impulses travel along the neurons and move from one neuron to the next across the synapses by means of
chemicals called neurotransmitters. It is through nerve impulses that the brain controls such activities as voluntary and
involuntary movement.
The brain is connected with the sense organs, muscles of the head, and internal organs of the body by 12 pairs of cranial nerves.
Some of the cranial nerves, called motor nerves, carry impulses from the brain to various parts of the body. Others, called
sensory nerves, carry impulses from the body back to the brain. Most pairs of cranial nerves contain one motor and one sensory
nerve; a few pairs contain sensory nerves only.
The brain consists of two types of tissue: (1) nerve cells, or gray matter; and (2) sheathed nerve fibers, or white matter. The
sheath is composed of myelin, a fatty protein that protects and insulates the fibers.
Tier Two:
Tier Three:
Prefixes/Suffixes
CephalChiasmFlaccFuniGanggliMeningPlex-
A large number of blood vessels carry nourishment to the brain. The brain extracts certain substances from the blood and
metabolizes them (that is, produces chemical changes in them) to produce energy. Glucose, its main source of energy, is
metabolized by a chemical reaction with oxygen carried in the blood.
The human brain is more complex and has more functions than the brain of any other animal. It is the seat of consciousness and
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the coordinator of the nervous system. Thought, memory, imagination, and other mental processes are functions of the brain.
Specific areas in the brain are responsible for language and emotions. The brain is the seat of sensations. All voluntary and some
reflex muscular movements are initiated and regulated by the brain. In addition, various parts of the brain control such
automatic functions as heartbeat, temperature regulation, digestion, and breathing.
The brain of the average human male weighs about 3 pounds (1.4 kg); the human female, 2.7 pounds (1.2 kg). At birth, a baby's
brain weighs only 11 to 13 ounces (310 to 370 g), but it grows rapidly during the first years of life. By the age of seven, a child's
brain has reached nearly its full weight and volume, after which its growth is slow. The brain of a human male is fully grown by
the 20th year, that of a female somewhat earlier. After the age of 20, the brain loses about one gram (0.04 ounce) of weight per
year.
How the Brain Is Protected
Brain tissue is very soft and easily injured. It is well protected, however, by the skull and by three membranes of connective
tissue, collectively called the meninges, between the skull and brain.
The outermost membrane is thick and tough, and fits closely to the inner surface of the skull. This membrane is called the dura
mater, which is Latin for "hard mother."
The innermost membrane is the pia mater, Latin for "tender mother." This thin membrane contains a network of blood vessels.
These blood vessels supply nourishment to the brain, and carry blood from its interior back to the heart. The pia mater conforms
exactly to the outer surface of the brain itself.
Between the dura mater and the pia mater is the arachnoid, or "spider-like," membrane. It is a soft, delicate, transparent tissue.
The subarachnoid space, between the arachnoid membrane and the dura mater, is filled with cerebrospinal fluid, a clear,
colorless liquid composed of protein, glucose, urea, and salts. It moistens the tissues of the brain and protects them from injury.
The brain is also protected by the blood-brain barrier, a network of tightly meshed capillaries (tiny blood vessels) that
selectively filter out harmful chemicals and waste products while permitting other substances, such as nutrients, to pass directly
into the brain. This barrier prevents harmful compounds in the blood from being absorbed by brain tissue.
Parts of the Brain
The brain itself consists of three main parts: a large forward part called the forebrain; a narrow middle portion called the
midbrain; and a rear part, called the hindbrain. It contains four cavities (hollow spaces called ventricles.)
The Forebrain, which is made up mainly of a mass of neurons called the cerebrum, occupies most of the skull cavity and accounts
for 90 percent of the weight of the entire brain. The surface of the cerebrum is a layer of gray matter called the cerebral cortex. It
has many folds, or convolutions, which greatly increase its area.
The longitudinal fissure, a deep cleft running from front to back, partially divides the cerebrum into right and left hemispheres. A
central band of nerve fibers called the corpus callosum connects the two hemispheres. It contains bundles of nerve fibers called
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nerve tracts that carry information between the two hemispheres. The corticospinal tract carries impulses from the cerebral
cortex to the spinal cord. Its fibers cross each other at the region where the medulla oblongata (an area in the hindbrain) meets
the spinal cord. Thus, the left hemisphere controls the movements and interprets the sensations of the right side of the body and
vice versa.
Each hemisphere performs unique tasks. The left hemisphere is responsible for logical thought, writing, and mathematical skills.
The centers of language are also located here. Broca's area, situated in the frontal lobe (the forward section of the hemisphere),
is responsible for the production of language. Wernicke's area, situated in the temporal lobe, a section above the ears, is
responsible for the comprehension of language. The two areas are connected by a bundle of fibers called the arcuata fasciculus.
Damage to these fibers will cause speech impairment. The right hemisphere is responsible for intuition, musical and artistic
ability, and analysis of visual patterns. Although each hemisphere is responsible for different functions, one can take over for the
other in the event of localized brain damage.
The cerebral cortex contains two specialized areas: the somatic sensory cortex and the motor cortex. They are separated by the
central fissure, a deep cleft perpendicular to the longitudinal fissure and extending across the roof of the brain.
The somatic sensory cortex receives sensory signals from the skin, bones, joints, and muscles. The motor cortex, parallel to and
in front of the sensory cortex, controls the voluntary movement of muscles. Almost every part of the human body has a specific
region controlling it in both the somatic sensory cortex and the motor cortex. Body parts that perform intricate movements, such
as the lips, hands, and legs, are controlled by large parts of the cortex. Body parts that perform gross movements, such as the
shoulders and trunk, are controlled by smaller areas. Adjacent regions in the brain control adjacent body parts.
The cortex of each cerebral hemisphere is divided into four sections, called lobes:
The Frontal Lobe, the forward, upper part of the cerebrum, includes the areas concerned with intelligence, judgment, emotional
reaction, and the movement of skeletal muscles.
The Parietal Lobe, in the upper, back area of the cerebrum, receives and interprets the sensations of pressure, temperature, and
position.
The Temporal Lobe, above the ears, is concerned with hearing, memory, and understanding of speech.
The Occipital Lobe, in the back part of the cerebrum, is concerned with vision and the interpretation of objects that are seen.
Each hemisphere contains a mass of nuclei called the thalamus (plural: thalami). It consists of gray matter that integrates a wide
range of sensations from the visual and motor cortexes. It also plays a role in emotions. Above each thalamus are two basal
ganglia, clusters of neurons that help regulate body movements. Beneath the thalami is the hypothalamus, a mass of nerve cells
and fibers that controls the reaction of the body to stress and to strong emotion. It also regulates the body's water balance,
temperature, appetite, sleepiness, and heart rate. Below and in front of the hypothalamus is the pituitary gland, which is partially
controlled by the hypothalamus.
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The pineal gland, or epiphysis, is a cone-shaped organ located beneath the corpus callosum. It is connected by nerves to the eyes
and is extremely sensitive to light. In response to darkness, it secretes melatonin, a hormone that is believed to induce sleep.
The olfactory bulbs, which govern the sense of smell, are located on the undersurface of the hemispheres. Nerves run from the
nose through these bulbs to the cerebrum.
The Midbrain contains tracts (bundles) of nerve fibers that connect with other parts of the brain and with the spinal cord. The
midbrain also has centers for auditory and visual reflexes, such as the contracting of the pupils.
The Hindbrain consists of three parts: (1) the cerebellum, behind and beneath the cerebrum; (2) the pons, beneath the midbrain
and opposite the cerebellum; and (3) the medulla oblongata, attached at its base to the spinal cord.
The cerebellum, like the cerebrum, has a convoluted surface. The chief function of the cerebellum is to coordinate and regulate
movements of the skeletal muscles. (The movements, however, are initiated and controlled by the cerebrum.) When the
cerebellum is damaged, ordinary movements directed by the cerebrum cannot be carried out. Limb movements become slow
and jerky, and speech may become slurred.
The pons is a smooth-surfaced bulge between the midbrain and the medulla oblongata. It contains tracts that connect the two
sides of the cerebellum, and tracts that connect other parts of the brain with each other and with the spinal cord. Many of the
cranial nerves pass through here. The pons controls the motor and sensory nerves to the eyes, jaw, face, and muscles. Together
with the cerebellum, it regulates posture and balance.
The medulla oblongata is smooth, without convolutions. It contains three important nerve centers: one affects the rate of
heartbeat; one controls breathing; and one produces the constriction of blood vessels to control the volume of blood supply to
the tissues. It is also the site where the nerves from the left hemisphere cross over to control the right side of the body and vice
versa. Reflex centers of vomiting and swallowing also lie in the medulla.
The midbrain, pons, and medulla oblongata together form a structure called the brain stem. Deep within the brain stem,
extending from the medulla to the midbrain, is a network of nerve cells and fibers called the reticular formation. The reticular
formation regulates the amount and speed of electrical activity in the cerebral cortex. Many sensory nerves feed into it. It is
believed to be the seat of consciousness.
Ventricles. There are four ventricles within the brain. These cavities are connected to each other and to the hollow core of the
spinal cord. The largest cavities are the two lateral ventricles, located in each hemisphere of the cerebrum. Beneath the lateral
ventricles is the third ventricle and under it is the fourth. Cerebrospinal fluid is formed and stored in the ventricles.
Within the lateral ventricles is the limbic system, a group of structures that controls emotions and behavior, stores memories,
and is involved in learning. It contains two masses of gray matter: the amygdale and the hippocampus.
Chemistry of the Brain
Since the early 1970's researchers have discovered that the brain contains more than 50 neurotransmitters, chemical substances
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that facilitate the transmission of nerve impulses between neurons. They interact with specific receptor sites in the brain to elicit
chemical changes. Some circulate throughout the body.
All neurotransmitters have chemical precursors. These are substances, composed of glucose and amino acids, that are produced
elsewhere in the body and are carried in the bloodstream. The precursors are able to cross the blood-brain barrier into the brain,
where they are eventually converted into neurotransmitters. The quantities of neurotransmitters in the brain are affected by the
consumption of certain foods and also by strenuous exercise.
Endorphins make up a family of neurotransmitters that act as natural painkillers. They moderate the amount of pain an
individual feels. They are composed of chains of amino acids called peptides.
Narcotic analgesic drugs, such as heroin or morphine, effectively reduce pain by occupying the same receptor sites and
producing the same interactions as endorphins. These drugs are often prescribed for severe pain or when there is a delay or
malfunction in the release of the natural painkillers.
Acetylcholine is a neurotransmitter that functions in storing memories, regulating moods, and controlling body movements.
Consumption of such foods as eggs, soybeans, and liver increases its production. All of these contain lecithin, which is converted
into choline in the liver. Choline is a chemical precursor that is converted into acetylcholine in the brain. Serotonin, a
neurotransmitter found only in the hypothalamus and midbrain, relieves depression, reduces sensitivity to pain, and induces
sleep. Its chemical precursor is tryptophan, which is found in the protein in meat, fowl, and fish. Norepinephrine is another
neurotransmitter that helps relieve depression. Its precursor is tyrosine, which is also found in protein.
Strenuous exercise increases the production of endorphins and norepinephrine. It is this increased production that causes
"runner's high"—an increased tolerance to pain and a state of euphoria experienced by many long-distance runners.
"brain." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=NS30825&SingleRecord=True>.
I Can Statements
The students can…
Describe the relationship among the brain, brain stem, and spinal cord.
Describe the covering of the brain and spinal cord.
Describe the formation and function of cerebrospinal fluid.
Describe the major functions of the spinal cord.
Describe the development of the major parts of the brain and explain the function of each part.
Discuss hemisphere dominance.
Explain the stages of memory storage.
Distinguish between the major parts of the pns.
Describe the structure of the pn and how its fibers are classified.
 Identify cranial nerves and list their major functions
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Instructional Strategies and Resources
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BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
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Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Nervous System III:
Academic Vocabulary/
Language
Tier Two:
Essential Understandings
The human brain is truly an amazing organ. Although it weighs only about 1.4 kilograms (3 pounds), this highly organized
collection of cells lets us communicate with others, perform mental tasks, remember homework assignments, understand
concepts, be aware of our surroundings, and move our body parts. However, the brain would be useless without its connections
to the rest of the body and to the outside world. In fact, as strange as it sounds, we do not experience our environment and the
events taking place within our bodies directly or in their entirety. Instead, we experience them by way of specialized sense
organs that send information to the brain. In other words, just about everything we know about the world comes to us through
our senses, and everything we do depends on receiving and correctly interpreting information from our external and internal
environments.
Sensation and Perception
Both sensation and perception are functions of the brain—specifically, a part of the brain called the cerebral cortex, or cerebrum
(see figure below). Nerve impulses from sensory receptors are transmitted to particular parts of the brain. The brain interprets
them as sensations, an awareness and localization of a stimulus. A stimulus is a change in the internal or external environment
that leads to a response. A perception involves giving meaning to a sensation based on what we have experienced and learned.
For instance, stepping on a tack will cause a sensation of pain, whereas an awareness of being injured would be considered a
perception. Perception is important in determining how we will respond to a particular stimulus.
Sensations, and the perceptions they evoke, begin with sensory reception, the detection of a stimulus (or, more accurately, the
energy of a stimulus) by sensory receptors. Sensory receptors are anatomical structures made up of special cells that respond to
specific changes in their environment (stimuli). In so doing, they provide the central nervous system (brain and spinal cord) with
information about conditions both inside and outside the body. In this way, sensory receptors are the physical links between
your central nervous system and the environment
Sensory receptors work by first detecting a stimulus and then translating that energy into electrical signals, which are conducted
by nerve cells, or neurons, to the central nervous system. Turning a stimulus into an electrical signal is called transduction (a
transducer is a device that changes one form of energy into another). Specialized sensory receptors are needed to detect stimuli
because the brain has no such ability. That is, the brain is designed to receive electrical signals from the nervous system; beyond
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Name
Explain
Describe
Distinguish
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AudChoroid
Cochlea
CornIris
Labyrinth
LaciLutMacula
Malle
OculOlfactPalpebral
PhotoSclerThermTympanVitre-
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that, it is essentially "blind" to all other forms of stimuli. This explains why neurosurgeons may perform procedures on the brain
of an awake patient. Only a local anesthetic is needed for the scalp because the brain cannot directly sense touch or pain.
The initial response of a sensory receptor to a stimulus is to change its cell membrane permeability to ions—how many and what
kinds of ions it lets through. In other words, in response to an appropriate stimulus, transport pathways for specific ions open
and/or close, depending on the type of stimulus and receptor
This, in turn, influences the movement of a charge across the cell membrane, resulting in a graded change in the membrane
potential (voltage), which is called a receptor potential. The magnitude of a receptor potential is directly related to how strong
the stimulus is. If a receptor potential is large enough, it may result in a conscious sensation by the brain (that is, a conscious
awareness of the stimulus). However, much of the sensory information that goes to the central nervous system is filtered out by
specific parts of the brain; as a result, no sensation is perceived for many stimuli. This is important because the brain would
otherwise be overloaded with too many signals to sort through. For instance, we are usually not aware of our muscle tension or
blood pH levels (pH meaning a measurement of the acidity or alkalinity of a solution). We also have the ability to listen to a
friend in a noisy restaurant, while simultaneously "tuning out" the myriad of other conversations and sounds around us.
Sensory Modality and Receptor Specificity
We are able to distinguish a variety of sensory stimuli because each kind of stimulus activates different types of receptor cells.
The term modality refers to the type of sensation a stimulus produces. Each category of sensation, such as touch, taste, or sound,
is a sensory modality. The features that characterize stimuli within a certain modality are called "qualities." For instance, light
can be red or blue, taste can be sweet or sour, and sounds can be high or low in pitch.
Each receptor has its own special sensitivity to stimuli. For example, a receptor for light does not react to sound waves, and a
taste receptor that responds to dissolved chemicals does not respond to light. This concept of receptors responding only to a
particular stimulus is called receptor specificity. Interestingly, and amazingly, many receptors can detect the smallest physical
unit of stimulus possible. For example, some receptor cells of the nose can respond to a single molecule of odor! The receptor
cells of the inner ear can sense motion of only a few angstroms (about the size of a single water molecule), and many
photoreceptor cells can detect a single quantum (photon) of light.
Receptors can be categorized in different ways based on:
the type of sensation (modality) to which they respond,
the location of the stimulus to which they respond, and
their structural complexity.
Classification of Receptors by Modality
Receptors that respond to chemicals in solution are called chemoreceptors. Some chemoreceptors are general receptors that
detect information about the total number of dissolved substances in a solution. For instance, osmoreceptors in your brain are
chemoreceptors that sense changes in the total solute (dissolved substances) concentration of the blood and make you thirsty
when this concentration increases. In contrast, other types of chemoreceptors respond to individual kinds of molecules. In this
case, the stimulus molecule binds to a specific site on the membrane of the receptor cell, which leads to changes in membrane
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permeability and alters the membrane potential. The chemoreceptors involved with taste and smell are of this type.
Receptors that respond to light are called photoreceptors. The eye contains two kinds of photoreceptors: rods (for vision in dim
light) and cones (for color vision). Thermoreceptors are sensitive to temperature changes and react to either heat or cold. The
body, in turn, uses this information to regulate both its surface and core (internal) temperature. Receptors that are stimulated by
touch, pressure, stretch, tension, or vibration are called mechanoreceptors. These include receptors in the organs for hearing and
balance (located in the inner ear) and many receptors in the skin, viscera (internal organs), and joints. Muscle spindle fibers are
specialized mechanoreceptors, called stretch receptors, that monitor the length of skeletal muscles.
Receptors that respond to potentially damaging stimuli and cause pain are called nociceptors. Stimuli that influence nociceptors
include trauma from blows or cuts, ischemia (poor blood flow), and too much stimulation by heat, radiation, and chemicals.
Although, for some people, chronic pain can be debilitating, the sensation of pain is necessary for survival because the stimulus
that causes pain often translates into a defensive reaction or withdrawal from danger. Imagine how difficult it would be for you
to survive if you lacked the ability to sense pain. Without a sense of pain, you wouldn't know when you should pull your hand
away from a hot stove or a sharp knife.
Classification of Receptors by Location
Receptors may also be classified according to the location of the stimulus to which they respond. Receptors that detect stimuli
that come from inside the body, such as those from the internal organs and blood vessels, are called interoceptors. They monitor
a variety of stimuli, including chemical changes in body fluids, tissue stretch, and body temperature. Although we are usually
unaware of the workings of interoceptors, they sometimes can produce feelings of visceral pain, nausea, stretch, pressure,
hunger, or thirst. Exteroceptors, on the other hand, respond to stimuli coming from outside the body. They include receptors for
touch, pressure, pain, temperature, vision, hearing, taste, and smell. Proprioceptors are located in skeletal muscles, tendons, and
joints, and in the ligaments and connective tissue that cover the bones and muscles. They are important for sensing the position
and movements of the body and its parts.
Classification of Receptors by Structural Complexity
Another way to classify receptors is by the complexity of their structure. The majority of receptors are considered simple
receptors, which means that they are made up of the modified nerve endings, or dendrites. Simple receptors involve sensory
neurons, which send signals from receptors to the brain and spinal cord. Simple receptors are found throughout the body and
monitor most types of general senses, which include tactile sensation (touch, pressure, stretch, and vibration), temperature (heat
and cold), and pain. In contrast, complex receptors are those we think of as the classical sense organs: localized collections of
cells associated with the special senses (hearing, balance, smell, vision, and taste).
Sensory Receptor Transmission
Sensory receptors transmit four kinds of information: modality, location, intensity, and duration. As stated previously, modality
is the type of sensation produced by a stimulus, such as vision, hearing, or taste. However, the actual nerve impulses that reach
the brain from virtually all kinds of receptors are identical in nature. How, then, does the brain distinguish between different
modalities if the input it receives is the same from all receptors? It does this by having nerve impulses arrive via different nerve
fibers, which, in turn, stimulate different centers in the brain. This arrangement is referred to as a labeled line code. In essence,
the brain has a number of "lines" (nerve fibers) that deliver information, which might loosely be compared to phone lines. Just as
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each phone line handles a different conversation, each nerve fiber represents a specific modality. In other words, even though all
the nerve impulses arriving in the brain are similar in nature (all are electrical signals), the impulses that arrive on one nerve
fiber have a different meaning for the brain than impulses arriving on another. For instance, any nerve impulses that go to the
brain from the optic nerve from the eye are interpreted as light. This helps explain why a blow to the eye, which can stimulate
the optic nerve, may initially be perceived as a flash of light rather than pain. Imagine what would happen to perception if the
nerve fibers leaving receptors were somehow mixed up before they arrived at the brain.
The location of a stimulus is encoded by the specific nerve fibers that are firing. That is, the brain has the ability to tell where the
stimulus is coming from based on information carried by nerve fibers. This ability is termed sensory projection. Sometimes the
brain can be fooled, however. One example is phantom pain—the perception of a feeling of pain in a limb after it has been
surgically amputated. Phantom pain demonstrates that sensory projection is a process that occurs in the brain—not at the level
of the receptor. The brain also can determine how intense a stimulus is based on the number and kinds of nerve fibers that are
firing and also on the amount of time between stimuli.
Receptor Adaptation
Many types of receptors have the ability to change their frequency of firing over time in response to a constant stimulus. This
process, called adaptation, refers to a decrease in responsiveness of receptors to continued stimulation. Phasic receptors
generate a burst of activity when they are first stimulated and then quickly stop transmitting impulses even if the stimulus
continues (in other words, they adapt quickly). Tactile receptors in the skin and hair receptors are two examples of rapidly
adapting phasic receptors. If these receptors were not phasic, we would sense a continual barrage of stimuli. For instance,
without sensory adaptation, you would feel every bit of clothing on your body all day long.
In contrast to phasic receptors, tonic receptors adapt slowly and therefore generate nerve impulses continually.
Proprioceptors—receptors located in skeletal muscles, tendons, and joints—are among the most slowly adapting tonic
receptors. This is significant because the brain must always be aware of body position, muscle tension, and joint motions.
Connections
A sensation is the awareness and localization of a stimulus (a change in the internal or external environment that evokes a
response). Once the brain is aware of sensations, it interprets them, helping us perceive what the stimulus is. Sensations and the
perceptions they evoke begin with sensory reception, the detection of a stimulus by sensory cells and its transduction into an
electrical signal. We are able to tell different types of sensory stimuli apart because they selectively activate different specialized
types of receptor cells.
Receptors that respond to chemicals in solution are called chemoreceptors, whereas those that respond to light energy are
known as photoreceptors. Thermoreceptors are sensitive to temperature changes, and those that are stimulated by physical
deformation are called mechanoreceptors. Nociceptors respond to potentially damaging stimuli and cause pain.
Receptors that detect stimuli arising from within the body are called interoceptors. They monitor a variety of stimuli, including
chemical changes in body fluids, tissue stretch, and body temperature. In contrast, exteroceptors respond to stimuli coming from
outside the body, and proprioceptors are located in skeletal muscles, tendons, and joints.
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Sensory receptors transmit four kinds of information: modality, location, intensity, and duration. This is accomplished, in part, by
having nerve impulses arrive in the brain via different nerve fibers, thereby stimulating different brain centers. This
arrangement is termed a labeled line code.
Receptors can change how often they fire over time in response to a constant stimulus. This process is called adaptation, and it
refers to a decrease in the responsiveness of receptors during continued stimulation. Phasic receptors generate a burst of
activity when first stimulated and then quickly stop sending impulses even if the stimulus continues. In contrast, tonic receptors
adapt slowly and therefore generate nerve impulses continually.
Light, Douglas B. "sensory receptors and sensation." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=HBSEN0001&SingleRecord=True>.
I Can Statements
The students can…
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Columbus City Schools
Differentiate between general senses and special senses.
Name the five types of receptors, state the function of each, and explain how they stimulate sensory impulses.
Explain the importance of stretch receptors in muscles and tendons.
Describe how the sensation of pain is produced.
Describe the differences among receptors associated with touch, pressure, temperature and pain.
Distinguish between static and dynamic equilibrium.
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Instructional Strategies and Resources
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BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
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Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Endocrine System:
Academic Vocabulary/
Language
Essential Understandings
The purpose of the endocrine system is to coordinate and regulate the functions of body cells, tissues, and organs. The endocrine
system regulates major life processes, such as metabolism, immune functions, the production of red blood cells, reproduction,
childbirth, and lactation, and controls internal body conditions such as osmolarity, water balance, heart rate, blood pressure, and
blood sugar levels. Endocrine glands produce and secrete chemicals called hormones that circulate in the blood and induce
functional changes in certain cells. Hormones, also called ligands because they bind to other macromolecules, travel throughout
the entire body via circulation, but only target cells, the types of cells that have receptors that specifically recognize the ligand,
respond to its presence. While both the nervous system and the endocrine system facilitate communication among different
body parts, the nervous system normally responds to stimuli that require an immediate response, such as removing one's hand
from a hot stove. The endocrine system generally manages slower or sustained responses that occur over minutes, hours, or
longer such as adjusting the degree of water retention during the production of urine, stimulating cell growth, or initiating sexual
maturation during puberty. The intensity of response to a hormone depends on its concentration, in contrast with the all-ornone action potentials that guide the transmission of nervous impulses. Both systems cooperate, however, to coordinate body
functions, respond to external and internal stimuli, and maintain homeostasis. For example, neurons that have hormone
receptors respond to hormonal signals. Some neurons secrete hormones directly into the circulatory system, and a number of
nerves directly innervate certain endocrine glands.
In addition to endocrine signaling, other types of chemical signals communicate information among cells. Neurotransmitters
carry signals across a synapse, a junction between a neuron and another neuron or a neuron and an effector cell. Autocrine
signals exert local effects on the same type of cells that release them. Paracrine signals affect cells in the immediate vicinity; they
are not transported in the blood. Exocrine glands produce and secrete substances such as mucus, sweat, and digestive enzymes,
but the secretions travel through ducts to the outside of the body or to cavities that are continuous with the outside of the body.
Special chemicals called pheromones leave the body of one individual and influence the behavior of other organisms. Not all
chemical signals fall into a single category. For example, some endocrine glands secrete hormones that act locally and at a
distance or that function as both neurotransmitters and hormones.
Tier Two:
Distinguish
Explain
List
Describe
Discuss
Name
Tier Three:
Prefixes/Suffixes
Cort-crin
DiuretEndoExoHormHyperHypoLactMedParaToc-tropic
Vas-
Hormone Synthesis, Transport, and Action
Hormones, chemical messengers that generally act over long distances, can be either proteins or lipids. Both are secreted by
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endocrine glands and travel in blood circulation, but the mechanisms by which they stimulate a response differ. Protein
hormones include polypeptide chains and glycoproteins (polypeptides with attached carbohydrate moieties). Growth hormone,
insulin, glucagon, and oxytocin are examples of protein hormones. Amines, amino acid derivatives such as epinephrine,
melatonin, and thyroid hormones, also function as hormones. Lipid hormones include steroids such as estrogen and testosterone
and fatty acid derivatives such as prostaglandins.
Protein hormones are hydrophilic (water- loving) and therefore are soluble in water. Ribosomes docked on the endoplasmic
reticulum (ER) assemble polypeptide chains according to information in the gene that encodes the hormone. During synthesis,
the polypeptide is extruded into the lumen (cavity) of the ER and then sent to the Golgi apparatus for processing. As for all
secreted proteins, the Golgi packages the protein hormones into vesicles for storage until the cell receives a signal triggering
secretion. At that time, the vesicles merge with the cell membrane and release the contents into the extracellular fluids of the
interstitium, the space between cells in a tissue. As are protein hormones, amines are stored intracellularly after synthesis until
time for secretion.
From the interstitial spaces, protein hormones move into blood circulation by leaky capillary walls. Because they are watersoluble, unique transport methods are not necessary. The hormones enter the capillary beds of various tissues, and when they
encounter cells that express receptors that specifically recognize the hormone, they bind to it. Protein hormones and amines
cannot diffuse through the phospholipid bilayer of cell membranes. They bind to the receptors located on the exterior surface of
the cell membrane and exert an effect without ever entering the target cell. Binding of a ligand to its receptor stimulates a
specific physiological response depending on the hormone and the type of target cell. Most protein hormones function by
activating second messenger systems that change the activity of proteins present in the cell. Other surface receptor—binding
hormones alter the permeability of the cell membranes by either opening or closing specific membrane channels. Because the
proteins or membrane channels are already present and waiting to be activated, the effects of protein hormone action occur
within minutes.
Second messenger systems mediate signal transduction pathways, mechanisms that carry information from a cell's exterior into
the cytoplasm, causing a cellular response. Signal transduction pathways involve a series of changes to intracellular proteins,
resulting in a cascade of cellular events. The response varies, depending on the type of target cell activated by the protein
hormone. Possible final effects include the induction of the expression of specific genes or the secretion of substances stored in
vesicles.
Steroid hormones are lipids and therefore are not soluble in water. Cholesterol is the precursor for all the steroid hormones.
Low-density lipoproteins (LDLs) carry cholesterol in circulation to the body cells, including the ones that synthesize steroid
hormones, called steroidogenic cells. Specific enzymes catalyze the stepwise conversion of cholesterol into the various steroid
hormones including progesterone, aldosterone, cortisol, dehydroepiandrosterone, testosterone, estrone, estradiol, and estriol.
The steroidogenic cells do not store steroid hormones; instead the hormones simply diffuse through the cell membrane into the
extracellular fluids. The body regulates the levels of circulating steroid hormones by controlling the rate of synthesis rather than
controlling the secretion, as in protein hormones.
Because steroid hormones are poorly soluble in water, they circulate in the aqueous plasma bound to transport proteins. When
bound, the hormone is not active, but the bound and unbound forms are in equilibrium, meaning a constant supply of unbound
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active hormone is readily available. In the unbound form, the steroid hormone can diffuse through capillary walls into tissue
beds, and even into the individual cells directly through the cell membranes. This is in contrast to protein and amine hormones,
which bind to receptors located on the outer surface of their target cells. Steroid hormone receptors exist inside target cells. If
the cells possess the specific receptors that recognize a particular hormone, the receptor and hormone (ligand) bind to form an
intracellular complex.
Steroid hormones act by stimulating the expression of certain genes. The protein products of the targeted genes bring about a
cellular or physiological response dependent on the function of that protein. Because new protein synthesis is time-consuming, a
delay of several hours precedes observable evidence of the steroid hormone's effect.
Steroid hormone receptors are usually in the nucleus but sometimes are found in the cytoplasm. The steroid hormone diffuses
from the bloodstream, through the cell membrane, and into the nucleus, where it finds and binds its receptor, forming a complex.
If the receptor is in the cytoplasm, the complex can diffuse into the nucleus from the cytoplasm. Most steroid receptors are
transcription factors, regulatory proteins that bind to deoxyribonucleic acid (DNA) and stimulate gene expression. Only certain
genes possess the specific DNA sequences, called hormone response elements (HREs), to which the complex binds and activates
gene expression. Activation leads to the synthesis of the protein encoded by that gene. The same hormone can stimulate the
expression of different genes in different cell types depending on the presence of other tissue-specific transcription factors.
Endocrine glands are organs located throughout the body that produce and secrete hormones into the extracellular fluid
surrounding cells. Hormone secretion is the main function of some glands, while other organs contain cells that synthesize and
secrete hormones but also have other important functions. For example, the main function of the stomach is to churn food and
begin the process of chemical digestion, but certain cells in the stomach also secrete gastrin, a protein hormone that helps
control appetite. The testes produce the male gametes, spermatozoa; the Leydig cells inside the seminiferous tubules of the
testes produce the steroid hormone testosterone.
Located in the ventral portion of the forebrain, the hypothalamus plays a major role in the coordination of many endocrine and
nervous system activities. The pituitary is a lima bean—shaped gland that is located at the base of the hypothalamus and
consists of two regions: the anterior and the posterior pituitary. The main functions of the hypothalamus include maintaining
homeostasis, controlling secretion of hormones from the posterior pituitary, and releasing chemical factors that regulate the
anterior pituitary. The brain relays information about both internal and external environmental conditions to the hypothalamus,
and the hypothalamus reacts by giving chemical commands to the pituitary gland. Specialized neurosecretory cells of the
hypothalamus synthesize two hormones, antidiuretic hormone (ADH) and oxytocin, which are stored in the posterior pituitary,
an extension of the hypothalamus consisting of neural tissue, also called the neurohypophysis. The anterior pituitary, also called
the adenohypophysis, consists of endocrine cells rather than neural tissue and functions in the synthesis of numerous hormones.
Four of the anterior pituitary hormones are tropic hormones, meaning they stimulate activity in other endocrine glands: folliclestimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), and adrenocorticotropic hormone
(ACTH). The anterior pituitary synthesizes and secretes the tropic hormones in response to hypothalamic secretions. The tropic
hormones stimulate another endocrine gland to produce yet another hormone that initiates an appropriate physiological change
in response to the information originally received by the hypothalamus. The table below, "Human Endocrine Glands and Their
Hormones," summarizes the role of several important human endocrine glands.
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Cullen, Katherine. "endocrine system." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=ELS0081&SingleRecord=True>.
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Distinguish between endocrine exocrine glands.
Explain what makes a cell a target for a hormone.
List the important functions of a hormone.
Describe how hormones can be classified according to their chemical composition.
Discuss the negative feedback mechanism regulate hormone secretion.
Explain how the nervous system controls hormone secretion.
Name and describe the locations of the major endocrine glands and list the hormone that they secrete.
Describe the actions of the various hormones and their contributions to homeostasis.
Instructional Strategies and Resources
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BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
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Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
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Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Blood:
Academic Vocabulary/
Language
Tier Two:
Essential Understandings
Blood
A fluid that is pumped by the heart and circulates throughout the body in the arteries, capillaries, and veins. The chief function of
blood is to carry nutrients, oxygen, and hormones to all tissues of the body and to carry waste products and carbon dioxide away
from the tissues. The science dealing with the study of blood is called hematology. Except for the last section, this article is
concerned with human blood. It deals with the makeup and function of blood; for information on how the blood is pumped
through the body, see circulation. Human blood is sticky, bright red to very dark red in color, and very slightly alkaline. It is
slightly heavier than water. Blood constitutes about 1⁄15 of a healthy person's body weight. The average adult has 8 to 12 pints
(3.8 to 5.7 liters) of blood and can lose one pint (.47 liter) without danger. Blood is a tissue of the body. The blood of all higher
animals, including that of humans, consists of a liquid called plasma and three kinds of cells. The cells, which float in the plasma,
are the platelets (or thrombocytes), the red blood cells (or erythrocytes), and the white blood cells (or leukocytes). About 55
percent of the blood in a human being is plasma; the rest consists of cells. Blood cells develop from other cells, called stem cells,
located in the bone marrow, spleen, thymus, and lymph glands.
Plasma
Plasma carries materials to and from the various tissues of the blood. It is a straw-colored liquid composed of 91 to 92 percent
water and 8 to 9 percent suspended or dissolved substances. These substances include food materials from the liver and
intestines, waste products of the cells, glandular secretions (hormones), enzymes, blood proteins, glucose, fats, antibodies, and
inorganic salts. Small amounts of oxygen, nitrogen, and carbon dioxide are also dissolved in plasma. Blood Proteins make up
about 7 percent of plasma. They consist of fibrinogen, albumin, globulins, and other substances. These
are special proteins that are produced in the liver, and are not the same proteins that the body uses for growth, tissue repair, and
energy. Their main function is to help maintain the proper consistency of the blood and to prevent the blood from losing too
much liquid to the body cells. Fibrinogen contains various substances, called clotting factors, that play an essential role in the
formation of blood clots. Albumin transports fatty acids to the adipose tissue, a layer under the skin where fat is stored. It is also
responsible for the regulation of osmotic pressure, the force causing the movement of water into and out of the red blood cells.
The most important globulins, the gamma globulins, are the main component of antibodies, substances that help fight infection.
Describe
Distinguish
Explain
Discuss
Summarize
Review
Define
Tier Three:
Prefixes/Suffixes
AgglutinBil-crit
EmbolErythrHemaHemoHeapLeuko-lys
Macor-osis
-poie
Poly-stasis
Thromb-
Glucose, or Blood Sugar, is an essential part of the plasma. It provides energy for the body and is necessary for the chemical
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stability of certain cells. Normally its concentration is 0.1 percent. If the amount is significantly reduced, a condition called
hypoglycemia results. If this condition is not treated, nerve cells in the brain can become affected. When this occurs, convulsions
and even death may result. If the amount is significantly increased, a condition called hyperglycemia< results. Prolonged
hyperglycemia, a symptom of diabetes mellitus, can lead to anorexia, kidney failure, atherosclerosis, vision impairment, and,
eventually, coma. The body obtains glucose from food elements stored in the liver and muscles. The nervous system, pancreas,
liver, and adrenal glands help keep the glucose concentration constant. Minerals in the blood include sodium, potassium,
calcium, magnesium, iodine, iron, and phosphorus. Minerals are essential in maintaining the osmotic pressure of blood and are
crucial to the regulation of the acid-alkaline balance of blood. Minerals also have many other important functions. For example,
calcium is vital to the clotting process, and iron is used in making red blood cells.
Red Blood Cells
The color of blood is due to the red blood cells. These cells, sometimes called red corpuscles, are tiny biconcave disks (disks that
curve inward on both top and bottom). Red blood cells are the most numerous of the cells floating in plasma. A red blood cell
consists of an elastic framework in which hemoglobin is deposited. Hemoglobin is composed of heme, a pigment containing iron;
and globin, a protein. The iron combines chemically with oxygen from the lungs, carrying it to the tissues and cells throughout
the body. Hemoglobin also transports carbon dioxide away from the tissues and cells. The redness of blood varies with the
amount of oxygen that is contained in the hemoglobin. Blood in the arteries is bright red because of the high content of oxygen.
Blood in the veins is darker because it has given up its oxygen to body cells. Except in a fetus, red blood cells are produced in the
red marrow of the bones. In a fetus, before the bones develop, red blood cells are formed in the liver and spleen. The body
produces between 2,000,000 and 10,000,000 new red blood cells each second. Because the red blood cells carry oxygen, the
oxygen concentration in the blood is lowered when their supply falls below normal. This deficiency stimulates the red bone
marrow to produce an excess supply of new red blood cells. The additional cells make up for hemorrhage (blood loss caused by
injury), a lack of oxygen at high altitudes, or destruction of large numbers of red blood cells by bacteria or chemicals. However,
the ability of bone marrow to produce red blood cells is limited. If too many are destroyed, a severe form of anemia results.
The average lifespan of a red blood cell is 120 days. After that time, it starts to lose its ability to transport oxygen. Red blood cells
are destroyed in the liver, spleen, and bone marrow by white blood cells called macrophages. Macrophages filter out iron from
the hemoglobin, which is then stored in the liver and spleen. Bilirubin, an orange-yellow pigment formed by the breakdown of
hemoglobin, is stored in the liver, where it combines with other substances to form bile. The rate of destruction of red blood cells
is controlled by the amount of oxygen in the blood at a given time. For instance, when the oxygen content in the blood is low, the
rate of destruction of red blood cells is decreased. Destruction of red blood cells is random—old as well as young red blood cells
are destroyed in the process.
White Blood Cells
The white blood cells, also called white corpuscles, are larger than the red blood cells and fewer in number. White blood cells are
also found in the lymph. They defend the body against infection. There are five types of white blood cells in human blood. All
have nuclei and all lack hemoglobin. Neutrophils make up 65 to 75 percent of the white blood cells. Each is composed of a lobed
nucleus surrounded by a rim of cytoplasm. The cytoplasm contains granular enzymes. Neutrophils are formed in the bone
marrow and collect in infected tissues, where they destroy microorganisms by a process called phagocytosis. In phagocytosis, a
cell engulfs a tiny organic body (such as a microorganism or another cell) and breaks it down into its chemical elements.
Lymphocytes make up 20 to 35 percent of the white blood cells. Each has a large spherical nucleus surrounded by a small rim of
clear cytoplasm. The two main lymphocytes are B-cells and T cells. B-cells originate and mature in the bone marrow, the spleen,
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and the lymph nodes. At maturity, they become plasma cells, the cells that produce antibodies. T cells originate in the bone
marrow and thymus; all mature in the thymus. Some T cells destroy infectious microorganisms; others regulate the production
of antibodies. Monocytes make up 4 to 8 percent of the white blood cells. A monocyte is a large, round cell with a kidney-shaped
nucleus. Monocytes develop into macrophages, which destroy microorganisms and old red blood cells by phagocytosis.
Eosinophils, or Acidophils, make up 2 to 5 percent of the white blood cells. The nucleus is horseshoe-shaped and the cytoplasm
contains granular enzymes. Eosinophils collect in large numbers in infected areas. They increase in number in response to
parasitic infections and bronchial asthma. Basophils make up about 0.5 to 1 percent of the white blood cells. The nucleus is large
and lobed. They are the source of heparin, a substance that prevents blood from clotting spontaneously in blood vessels. White
blood cells are often called the "scavengers of the blood" because of the way in which they remove foreign substances. Except for
the lymphocytes, these cells move in the manner of the one-celled organisms called amoebas. Like an amoeba, a white blood cell
pushes out a portion of itself and then the rest of the cell flows in the same direction. White blood cells are especially numerous
in inflamed tissues. They are attracted to sites of injury by chemical substances released by the injured cells. Many white blood
cells die at these sites. The dead white blood cells, dead bacteria, and dead tissue cells form pus.
Platelets
Platelets are small, colorless, rod-shaped bodies. They are the smallest particles in the blood. Platelets are formed in bone
marrow and are composed of cytoplasm. The number of platelets per cubic millimeter of blood is approximately 140,000 to
400,000. Their main function is to aid in the clotting, or coagulation, of blood.
Clotting of Blood
Clotting factors in plasma act together with platelets to form blood clots. Platelets accumulate at the site of an injured blood
vessel. This accumulation produces a platelet plug at the site of damage, which retards bleeding until clotting factors can be
activated by a protein called tissue factor (TF). TF is found on the exterior surface of most cells outside the circulatory system.
When, due to an injury, blood comes into contact with one or more of these cells, the TF on them combines with a protein
circulating in the bloodstream, factor 7 (or Hageman factor), yielding a substance called the TF-7 complex. This substance
triggers a series of reactions involving clotting factors in the fibrinogen. In the most important of these reactions, the clotting
factor prothrombin is converted into thrombin, an enzyme. Then, thrombin converts the blood protein fibrinogen into a
substance called fibrin. Fibrin, a mass of tangled strands, traps red and white blood cells. This mass, together with the trapped
cells, is called a blood clot. At first the clot has a jellylike consistency. It soon begins to solidify and shrink, exuding a clear, strawcolored fluid. This fluid, called blood serum, consists of plasma that lacks fibrinogen. When the clot is completely dry, it is called a
scab. Clots also form, by a somewhat different process, within blood vessels whose walls have been damaged by infectious
organisms, such as bacteria. The clot, called a thrombus, is a means of temporary repair until new tissue is formed. If the clot
extends across the entire blood vessel and prevents the passage of blood, it may cut off the blood supply to nearby tissue.
Sometimes a clot will break loose from the point of origin and will be carried in the blood to another vessel, which it may then
block. This type of clot is called an embolus. A clot located in a blood vessel in the brain can lead to a stroke. In some persons,
certain diseases or conditions, such as arteriosclerosis or rheumatic heart disease, may lead to blood clots within the blood
vessels. In such cases, anticoagulants, such as coumarin, are prescribed. Anticoagulants can prevent the formation of clots in the
bloodstream. In some cases, anticoagulants, such as streptokinase and tissue plasminogen activator, can help dissolve a blood
clot that has already been formed. Since aspirin prevents platelets from sticking together, small doses (one 325-milligram tablet
a day) may reduce the risk of blood clots that can lead to heart attacks. Daily exercise also reduces the risk of developing blood
clots and heart attacks.
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Antibodies
The production of antibodies is triggered by an invasion of foreign substances, such as bacteria, called antigens. Antibodies
circulate in the bloodstream. They are usually effective in warding off infections, and they also can provide immunity to various
diseases.
Blood Transfusion and Blood Types
A transfusion is the passing of blood or blood components from a healthy person to an ill or injured person. Blood is taken from a
donor, and it is usually stored and given to a recipient at a later time. In autologous transfusions, persons are given transfusions
of their own blood. An autologous transfusion is used mainly in certain types of elective surgery; several weeks prior to surgery,
the patient donates one or two units of blood, which are then stored for eventual use during or after surgery. In intraoperative
autologous transfusions, special procedures are used during surgery to recover blood that would otherwise be lost and recycle it
back into the body. When transfusions were first performed, they sometimes caused death. Long investigation showed that there
are four main types, or groups, of human blood and that only some of these types can be mixed successfully. In 1902, Dr. Karl
Landsteiner, an Austrian-American pathologist, classified blood into the following types: A, B, AB, and O. Types A and O are the
most common, and type AB is the rarest. Blood types are determined by heredity. Blood can be given safely, as a rule, to a person
who has the same blood type as the donor. (The main exception, assuming that the donor is healthy, involves a substance called
the Rh factor and is discussed in the next section of this article.) Where types differ, only certain donors and recipients are
compatible. If a person given a transfusion receives the wrong type of blood, a substance in his or her own blood will cause the
red blood cells of the new blood to agglutinate, or clump. Tiny clots are formed, which block the capillaries. Even when the blood
is properly matched there exists the danger of transmitting certain diseases, including hepatitis and AIDS, through the blood.
Whole blood (plasma and cells) is generally given to patients with illnesses that affect the ability to produce red blood cells or
other cells. In injuries involving an excessive loss of blood, plasma or serum may often be used. Red blood cells can be given to
persons with an inadequate supply of red blood cells, such as those with anemia. Platelets are often given to leukemia patients
undergoing chemotherapy. Plasmapheresis is a process of separating the cells from the plasma by using a centrifuge, a machine
that separates substances of different densities. Components of the plasma, such as albumin, gamma globulin, and fibrinogen,
can then be separated and used in transfusions. Albumin is injected into persons suffering from shock or from the loss of fluid
that accompanies a severe burn. Gamma globulin, which is rich in antibodies, is used to prevent or treat infectious hepatitis,
chicken pox, and measles. It is also given to leukemia patients undergoing chemotherapy. The clotting factors in plasma are often
separated and given by transfusion to persons whose blood does not clot properly. Hospitals maintain blood banks in which
supplies of blood and blood components are available. An anticoagulant—a substance that keeps blood in a fluid form—is added.
Whole blood and red blood cells can be stored under refrigeration for up to six weeks. Red blood cells can be stored frozen and
remain usable for up to 10 years. Platelets are stored at room temperature for up to five days. Plasma can be frozen and stored
for up to one year. In the late 1970s, synthetic blood was developed. Synthetic blood is made from perfluorocarbons, a family of
synthetic organic compounds that can transport oxygen. The use of synthetic blood is chiefly experimental. During certain
surgical procedures involving the heart, synthetic blood can be used to supply oxygen directly to the heart. Synthetic blood does
not actually take the place of blood, but supplements the patient's blood.
The Rh Factor
The Rh factor is a hereditary substance found in the red blood cells of 85 percent of all human beings. A person who has this
substance in the blood is said to be Rh positive. Those who lack it are Rh negative. The presence of the Rh factor was first
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detected in 1940 by mixing a sample of human blood with the blood of rhesus monkeys. (The term Rh comes from rhesus.) When
the human sample contained the Rh substance, its red blood cells combined, forming clumps. These clumps occurred because the
blood of the monkeys lacked the Rh substance and produced antibodies to destroy it. The same process occurs in the blood of
persons who are Rh negative. When such a person receives blood from an Rh positive donor, the blood produces small amounts
of antibodies. After two or three transfusions, there is an increase in the production of these antibodies, called anti-Rh
antibodies, which causes the red blood cells to collect in clumps. The problem is avoided by using Rh-negative blood for the
transfusion. When a woman who is Rh negative conceives a child who is Rh positive, her blood may develop anti-Rh antibodies.
This occurs when red blood cells from the fetus cross the placenta and enter the mother's bloodstream. The anti-Rh antibodies
that she develops cross the placenta, passing into the bloodstream of the fetus. This causes the fetus's red blood cells to collect in
clumps, producing anemia or liver damage. The anemia can result in mental retardation and hearing loss or, in severe cases,
death. Amniocentesis, a process in which samples of fluid are withdrawn from the amniotic sac (the sac that surrounds the
fetus), is used to determine whether anti-Rh antibodies from the mother have crossed the placenta. If so, the severity of red
blood cell destruction can be determined by measuring the amount of bilirubin in the blood. Bilirubin is extremely toxic to the
fetus; if the content is found to be high, the baby is usually delivered prematurely and given a blood transfusion shortly after
birth. This transfusion, called an exchange transfusion, is performed to remove anti-Rh antibodies, destroyed red blood cells, and
bilirubin from the blood. Up to 85 percent of the blood can be removed and replaced. The baby is usually given Rh-negative
blood to prevent further red blood cell destruction by any remaining anti-Rh antibodies in the blood. The new blood helps build
up the hemoglobin level. The mother does not usually develop these antibodies during the first pregnancy. However, her body
may produce anti-Rh antibodies after the child is born, which would affect the next pregnancy. As a precaution, she is usually
given injections of gamma globulin, which prevent her body from producing anti-Rh antibodies before the next pregnancy.
"blood." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=NS30590&SingleRecord=True>.
I Can Statements
The students can…
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Columbus City Schools
Describe the general characteristics of blood, blood elements, and the major functions.
Distinguish between the formed elements of the blood and the liquid portion of blood.
Describe the origin of blood cells.
Explain the significance: rbc counts and how they are used to diagnose disease.
Discuss the life cycle of the rbc.
Summarize the control of red blood cell production.
Distinguish among the five types of white blood cell, stating the functions of each.
Describe the blood platelet and explain its function.
Describe the function of each major components of plasma.
Define homeostasis and explain the mechanisms that help to achieve it.
Review the major steps in coagulations.
Explain how to prevent coagulation.
Explain blood typing and how it is used to avoid adverse reactions following blood transfusions.
Describe how blood reactions may occur between fetal and material tissue.
2015-2016
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Instructional Strategies and Resources




BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
Columbus City Schools
2015-2016
59
Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Cardiovascular:
Academic Vocabulary/
Language
Essential Understandings
Parts of the Cardiovascular System
The heart acts as a pump that contracts and expands rhythmically to force the blood through a network of blood vessels—the
arteries, veins, and tiny capillaries—to and from all parts of the body.
The arteries carry blood from the heart to all parts of the body. The arteries end in countless networks of tiny blood vessels (the
capillaries), which transfer blood and its nutrients to various tissues of the body. Other capillaries then conduct the blood to the
veins, which carry it back to the heart.
Blood circulation follows two different circuits. The circuit to and from the lungs is known as the pulmonary system. The circuit
to and from the rest of the body is the systemic system. The right side of the heart receives blood from the systemic system and
pumps it to the lungs. The left side of the heart receives blood from the pulmonary system and pumps it out to the rest of the
body.
The heart pumps blood at a rate of about five quarts (4.7l) a minute. A drop of blood takes 30 to 60 seconds to travel through the
entire pulmonary and systemic systems.
Circulation through the Heart and Lungs
The heart has four chambers. On the right side are the right atrium (or auricle) and right ventricle; on the left side are the left
atrium and left ventricle. There is no opening between the right and left sides of the heart.
Blood from the body, or systemic, system enters the right atrium of the heart through two large veins, the venae cavae. The
upper, or superior vena cava, drains blood from the upper part of the body and arms; the lower, or inferior vena cava, drains
blood from the lower part of the body. The atrium contracts and forces the blood through the tricuspid valve down into the right
ventricle. (Valves prevent blood from flowing in the wrong direction.) When the right ventricle is filled, it in turn contracts and
forces the blood out of the heart through the pulmonary semilunar valve into the pulmonary arteries, which lead to the lungs.
Tier Two:
Discuss
Identify
Trace
Compare
Explain
Tier Three:
Prefixes/Suffixes
AngioAtherBradyDiastoleEdem-gram
LunMyoPapillPhlebSclerSynSystoleTachy-
The arteries branch out into finely divided capillaries that line the walls of the air sacs, or alveoli, of the lungs. The blood gives up
Columbus City Schools
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60
carbon dioxide and takes on fresh oxygen through the thin walls of the capillaries. The dark blood from the veins now becomes
bright red as oxygen combines with hemoglobin, a chemical compound in the blood cells. From the air sacs of the lungs the blood
enters the pulmonary veins and is carried back to the heart, into the left atrium.
The left atrium forces blood through the bicuspid valve into the left ventricle. When the left ventricle is filled, it contracts and
forces the blood out of the heart through the aortic semilunar valves into the aorta, a large artery.
Circulation through the Body
The aorta branches out into other arteries leading to different parts of the body. The arteries subdivide into smaller blood
vessels, the arterioles, which branch into the narrow capillaries. The capillaries have thin walls and permit the rapid transfer of
oxygen and food to the tissues, and the absorption by the blood of waste products.
As the blood travels through different parts of the body it distributes food, oxygen, and other substances, and absorbs wastes.
For example, in the small intestine the blood absorbs digested food, salts, and water. It gives up urea, uric acid, salts, water, other
wastes, and heat in the kidneys, and takes up insulin in the pancreas. In the liver the blood takes up urea and heat, and either
absorbs or gives up glucose, depending on the concentration of sugar in the blood. Both arteries and veins carry food and waste
matter, although only the arteries carry fresh oxygen.
After exchanging materials with the cells, the blood is delivered from the capillaries to the venules, tiny veins that merge to form
larger veins. The blood is now called venous. The many veins of the body empty into the two large veins, the venae cavae, which
transport blood back to the right atrium of the heart. The cycle of circulation is then repeated.
Since the heart and blood vessels are so intimately involved in circulating the blood throughout the body; the diseases affecting
them are collectively called cardiovascular diseases.
Pulse and Blood Pressure
The ventricles of the heart contract at a normal rate of 66 to 88 times a minute. With each contraction blood is forced into the
arteries, causing the regular throbbing that you can feel as your pulse.
The period during which the heart chambers contract is called systole. It is marked by an increase in pressure on the artery
walls. The period during which the chambers expand and fill with blood is called diastole, and is marked by a drop in pressure.
Blood pressure, which is measured in millimeters of mercury, is expressed as two figures, the systolic over the diastolic. The
figures represent the maximum and minimum amounts of pressure on the artery walls. An average reading for persons 20 years
old is about 120 over 80; however, there is much normal variation between individuals. Blood pressure tends to increase with
age. By measurement of the pulse and blood pressure a physician can decide whether the heart is pumping well enough to
maintain adequate pressure and flow.
Blood in the veins is under much less pressure than blood in the arteries, because the force is largely used up in sending blood
through the arteries. Blood will spurt out from a cut artery, whereas it flows steadily from a vein. Veins have valves that prevent
blood from flowing backward, away from the heart, and circulation of the venous blood is partly controlled by movement in the
surrounding muscles.
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"circulation (physiology)." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=NS40590&SingleRecord=True>.
I Can Statements
The students can…
□
□
□
□
□
□
Discuss the functions of the organs of the cardiovascular system.
Identify and locate the major parts of the heart and discuss the function of each.
Trace the pathway of blood through the heart and the vessels of the coronary circulation.
Describe the cardiac cycle and explain how the heart sounds are produced.
Compare the structure and functions of the major types of blood vessels.
Explain how blood pressure is produced and controlled
Misconceptions




The heart beats as a single unit, not as four independent chambers.
There is only one type of blood – not oxygen rich and oxygen poor.
Blood does not carry nutrients for body – is the highway of homeostasis.
All hearts are the same.
http://theinnerhuman.weebly.com/misconceptions.html
Columbus City Schools
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Instructional Strategies and Resources




BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
Columbus City Schools
2015-2016
63
Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Lymphatic/Immunity:
Essential Understandings
Unlike some of the other systems of the body, it is not easy to recognize all of the players of the immune system (see figure
below).
The Immune System
Although there are three basic types of muscles, they all share certain characteristics and it is easy to see that they make up a
cohesive muscular system. Likewise, although bones come in all shapes and sizes, they are more alike than they are different,
and, as a result, the skeletal system is fairly easy to identify. The immune system, on the other hand, is made up of a wide variety
of components. Some of these components exist as single cells. Others are specific sets of tissues, and still others are complex
organs. We find parts of the immune system throughout the body, and we often mistake them for parts of other body systems. In
fact, in some cases the components of the immune system are integral parts of other systems of the body.
In this entry, we will begin to identify the players in the immune system. We will not delve into their specific functions in detail
here. For the sake of convenience, we will cluster these various immune system components into four categories: individual
cells, tissues, organs, and multiorgan systems. We will begin our exploration with the most basic of these classes, the individual
cells.
Individual Cell Types Important to the Immune System
The most important individual cells of the immune system are the many kinds of white blood cells (see figure below).
Academic Vocabulary/
Language
Tier Two:
Describe
Identify
Explain
Distinguish
Tier Three:
Prefixes/Suffixes
Auto-gen,
HumorImmuneInflammNodPatho-
Although these cells differ in appearance and function, they are all derived from the same source; in fact, all blood cells are
generated by red bone marrow, the soft central core of many of the long bones of the body. Within the bone marrow are a group
of special cells, called stem cells. These cells are "undifferentiated" and can give rise to different types of cells. Once a cell
differentiates, it can make additional copies of itself only when it undergoes mitosis, but an undifferentiated cell can divide and
generate multiple types of cells. The process of making blood cells is called hematopoiesis. Hematopoiesis gives rise to
erythrocytes, or red blood cells, which are vital in transporting oxygen and carbon dioxide throughout the body, and to
leukocytes, or white blood cells, which are critical for the immune response. You may have also learned that platelets are a type
of blood cell. Actually, platelets, which are crucial for blood clotting, are fragments of blood cells, but they too are derived from
Columbus City Schools
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the stem cells in red bone marrow. Since our focus is on the immune system, we will dispense with further discussion of
erythrocytes and platelets here and will focus on the leukocytes.
As bone marrow stem cells begin to divide, they can differentiate into a major precursor cell class called the leukocytes.
Leukocytes further differentiate into two major classes: the phagocytic family and the lymphoid family. The phagocyte precursor
cell can then differentiate further. Two derivatives of this cell are the mononuclear leukocytes and the polymorphonuclear
leukocytes (granulated leukocytes). These long, technical names may seem a little intimidating, but if you break them down into
the meanings of their root components, you will learn something about the structure of the cells. For the mononuclear
leukocytes, "mono" means "one" and "nuclear" means "nucleus." All of these cells contain a single nucleus. These cells are also
called agranulocytes because they do not contain granules of special proteins or chemicals in special organelles of the cytoplasm.
Mononuclear leukocytes develop into monocytes, which make up about 8% of all leukocytes in the blood. Later, some of these
monocytes can further differentiate into macrophages, cells important in fighting infection. Macrophages are not found in the
bloodstream itself, but seem to develop from monocytes as the monocytes squeeze through the walls of capillaries and move into
the fluids that bathe the tissues of the body.
Polymorphonuclear leukocytes are more complex than mononuclear leukocytes. Poly means "many," morpho means "shape,"
and nuclear means "nucleus." Thus, these cells have nuclei with differing shapes. Polymorphonuclear leukocytes can develop
into three different types of cells. Neutrophils are polymorphonuclear leukocytes that have neutral granules, "neutral" meaning
that they have no net charge. These cells stain poorly because most of the dyes used to stain human cells do so through charged
groups on the stain surface. Because the neutrophils are electrically neutral, they do not bind stains well. The neutrophils are the
largest class of polymorphonuclear leukocytes, constituting more than 50% of all leukocytes.
A second class of this family is the eosinophils. Eosin is a red dye that has a net negative charge; the granules of eosinophils have
a net positive charge, so they bind to this dye. Eosinophil means "eosin loving." Although the eosinophils make up only a small
part of the total leukocyte population in the blood (about 6%), they are very important in fighting infections caused by fungi,
protozoa, and worms.
The final group of polymorphonuclear leukocytes is the basophils. Basophils contain granules made of compounds with a net
negative charge so they bind to positively charged dyes, which are also called basic dyes. Methylene blue is one such dye, and
when added to a blood smear, basophils will bind the methylene blue, taking on a blue color for their granules. The basophils are
the least numerous of the leukocytes, making up less than 1% of the total leukocytes in the blood. Basophils seem to be closely
related to another group of cells, called mast cells. Both basophils and mast cells contain a compound called histamine. When
activated, these cells release the histamine, resulting in an inflammatory reaction. Basophils and mast cells are directly involved
in allergic reactions, which is why we will often take antihistamines to fight the symptoms of allergies (stuffiness, runny nose,
etc.). Antihistamines block the action of histamine.
The second major family of leukocytes derived from bone marrow stem cells is the lymphoid family. Depending on where in the
body these cells mature, they develop into one of two cell types. When the lymphoid precursor cell remains in the bone marrow
to mature, it becomes a B lymphocyte, or B cell. B cells are the principal cells for making antibodies. When the lymphoid
precursor cells migrate to the thymus, a gland that lies in front of the heart, the precursors become one of a number of types of T
lymphocytes, or T cells. T cells mediate a process known as cell-mediated immunity. They are also critical in regulating the
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intensity of the immune reaction. There are three major divisions of T cells. Cytotoxic T cells (TC cells) carry out cell-mediated
immunity. T-helper cells (TH cells) are central in activating immune responses, and suppressor T cells (TS cells) reduce the
intensity of the immune system and also probably play an important role in helping our bodies distinguish our own tissues and
cells from those of invading materials.
A third class of lymphoid cells that is less well understood is the non-B, non-T, or null lymphocytes. These cells can be
distinguished from B and T cells by the absence of certain surface structures. They tend to fight infections, but do so
nonspecifically, whereas B cells and cytotoxic T cells are programmed to attack very specific foreign antigens.
Tissues of the Immune System
In addition to the cells that directly fight infection or regulate the immune process, there are also clusters of cells that form
tissues critical for immunity. The tonsils are a ring of lymphoid tissue located at the back of the mouth, just at the top of the
throat. Your doctor or nurse will "swab" the tonsils with a sterile applicator when he or she is checking for strep throat. Closely
related tissues found in the nose are the adenoids. These patches of tissue are positioned where the nasal area opens into the
throat. The tonsils and the adenoids are rich in all types of leukocytes. When a foreign organism enters the body through the
mouth or nose, it is usually transported to either the tonsils or the adenoids where the cells of the immune system launch an
attack. We have learned only in recent years the important role that these tissues play in preventing infections that enter
through the respiratory system. Now that we know the critical role the tonsils and the adenoids play in fighting infection, doctors
are much more hesitant to remove them.
Another important mass of lymphoid tissue is the appendix. As with the tonsils, it was much more common to remove a person's
appendix a generation or two ago because we did not know its function. We assumed that it was unessential and therefore if it
became inflamed (which would not be unusual for a lymphoid tissue), we thought it could be removed with no ill effects.
Although we still do not completely understand the role of the appendix, it is probably important in protecting the lower
digestive tract and the body cavity from infectious agents that enter the body in food or water.
The final general group of lymphoid tissues is the Peyer's patches. Peyer's patches are small pockets of lymphoid tissue found in
the intestines. They may play a protective role similar to that of the appendix. Closely related to Peyer's patches are skinassociated lymphoid tissue (SALT) and mucosa-associated lymphoid tissue (MALT). These patches of tissue are located below
the surface of the skin and mucous membranes, respectively. They are critical in preventing infections caused by infectious
organisms that cross these natural barriers. The importance of SALT has been demonstrated in burn patients. Severe burn
patients whose SALT patches are intact and functional are much less likely to have their burns become infected than are those
whose SALT patches are damaged by the burn.
Organs of the Immune System
An organ is a collection of different tissues that work together to perform one or more important functions. The organs of the
immune system can be divided into two major classes. Primary lymphoid organs include the bone marrow and the thymus. They
are essential for the production and development of the various classes of lymphocytes. Bone marrow is the site of blood cell
production, including lymphocytes. The bones most important in this process are the vertebrae, the ribs, the sternum, the long
bones of the arms and legs, and the pelvis. Bone marrow not only gives rise to all types of blood cells, but it is also the location for
the specialization of B cells. The second primary lymphoid organ is the thymus. As mentioned previously, the thymus is a small
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organ located just in front of the heart. The thymus is critical in the development and maturation of T cells.
The secondary lymphoid organs are the lymph nodes (see figure below) and the spleen. Lymph is fluid that is forced out of the
blood vessels and bathes the body tissues directly. It is returned to the circulatory system by a system of lymph vessels that arise
in the body tissues and eventually dump the lymph into a vein near the heart. Lymph transports many of the important
components of the immune system. Before the lymph is returned to the circulatory system, it passes through masses of lymphoid
tissue called lymph nodes. Collectively, the lymph, lymph vessels, and lymph nodes make up the lymphatic system.
Have you ever noticed that sometimes when you have a sore throat, the "glands" in your neck get swollen? Those glands are
actually lymph nodes that are fighting infection. Because they activate the immune system within their structure, the tissues of
the lymph nodes become inflamed and sore. Lymph nodes are scattered throughout the body, but especially along the neck and
trunk. There are significant concentrations of lymph nodes in the area of the hip joint, along the abdomen, under the sternum
and around the breasts, and under the arms and into the neck. The word "node" means a point of connection. The lymph nodes
are the locations where various branches of the lymphatic system come together. We will discuss the lymphatic system in the
final section of this entry.
In addition to the lymph nodes, the spleen is another very important secondary lymphatic organ. The spleen is located in the
upper part of the abdomen, just below the diaphragm. The spleen is fed by a large number of blood vessels, and, as a result, the
blood spends a significant amount of time in the spleen. Unfortunately, the spleen is not very well protected by the body. It is not
unusual when a person has a serious blow to the abdomen, as one might experience in a serious automobile accident, a fall, or a
crushing blow, for the spleen to rupture. Because so much blood flows through the spleen, a rupture of the spleen can cause
massive internal bleeding, and, as a result, it may have to be removed to prevent the victim from bleeding to death. Fortunately,
this is fairly routine surgery, and most patients recover from a splenectomy. Unfortunately, without a spleen, these individuals
typically suffer from many more infections than persons with a functional spleen, indicating the importance of this organ in
immune defense.
Lymphatic Circulation
We tend to think of the circulatory system as a closed loop of tubes—arteries, capillaries, and veins—that transport blood from
the heart to the lungs and to the body. However, the circulatory system is not completely closed. The blood is under pressure,
and this pressure forces some of the fluid of the blood, the plasma, through the walls of blood vessels, mainly the capillaries.
Once the fluid leaves the circulatory system and enters the tissues, it is referred to as lymph. Obviously, if fluid leaks out of the
circulatory system and gets out into the tissues, there has to be a way to return it to the bloodstream. The fluids around the
tissues drain into tiny tubes called lymphatic vessels. These lymphatic vessels merge into larger vessels at intersections marked
by lymph nodes. Ultimately, all of the lymphatic vessels and lymph nodes merge into the final components of lymphatic
circulation, the thoracic duct and right lymphatic duct. These ducts empty the lymph from the lymphatic system into large veins
near the heart, thus returning the fluid to the circulatory system.
Additionally, monocytes, one of the classes of white blood cells, can also squeeze through the walls of the capillaries when
signaled to do so. When they do, these cells undergo another transformation and become macrophages. Macrophages are large
polymorphonuclear leukocytes that wander around the tissues looking for foreign invaders. When they find them, they engulf
the proteins, bacteria, viruses, or whatever these foreign invaders happen to be and destroy them. Moreover, they will actually
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use pieces of these destroyed materials to activate the immune system to fight even harder.
Stewart, Gregory J. "cells, tissues, and organs of the immune system." Science Online. Facts On File, Inc. Web. 18 Aug.
2015. <http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=HBIS0003&SingleRecord=True>.
I Can Statements
The students can…
□
□
□
□
□
□
□
□
□
Describe general function lymphatic system.
Identify and describe major parts of lymphatic pathways.
Describe how tissue, fluid and lymph form, and explain lymph function.
Explain how lymphatic circulation is maintained, and describe the consequence of lymphatic obstruction.
Describe a lymph node and its major functions.
Distinguish between innate (nonspecific) and adaptive (specific) defenses.
Distinguish between primary and secondary immune responses.
Distinguish between active and passive immunity.
Explain how allergic reactions, tissue rejection reactions, and autoimmunity arise from immune mechanisms.
Instructional Strategies and Resources




BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Columbus City Schools
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68
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
Columbus City Schools
2015-2016
69
Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Digestive System:
Academic Vocabulary/
Language
Essential Understandings
Stages of Digestion
The four processes of digestion are ingestion, digestion, absorption, and elimination. Ingestion is the process by which an animal
takes food substances into the body, for example, by tearing pieces of leaves from a plant with mouthparts, sucking nectar from a
flower, filtering surrounding water for food particles, or grasping and placing large pieces of food into the mouth. Usually, the
body cannot utilize the form of food introduced. Mechanical processes such as chewing or grinding help break food into smaller,
manageable pieces that digestive juices can efficiently dissolve. Macromolecules such as proteins, lipids, nucleic acids, starches,
or other polysaccharides are too large to be absorbed by body cells. The process of digestion breaks down the food into usable
fragments. Enzymes secreted by cells of digestive tissues or accessory glands reduce the macromolecules into individual
subunits such as amino acids, monosaccharaides, fatty acids, or nucleotides. Absorption is the uptake of these smaller nutrient
substances from the digestive compartment. In primitive invertebrates, individual body cells absorb the nutrients directly from a
gastrovascular cavity, but in most animals, a separate circulatory system often transports the nutrients throughout the body. The
indigestible material remaining in the digestive tract after absorption exits the body as feces through a process called
elimination.
Human Digestive System
The digestive tract (gastrointestinal tract or GI tract) of humans consists of a long tube through which food passes as it is broken
down, digested, and absorbed or eliminated and several accessory organs and glands. The digestive tract includes the mouth,
pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus. The accessory glands are the salivary glands, the
pancreas, the liver, and the gallbladder. The layers of the digestive tract share similar qualities all the way from the esophagus to
the anus. Epithelial cells that line the tract transport substances into and out of the lumen and produce and secrete enzymes,
mucus, and hormones. Epithelial cells lining the GI tract only live for a few days before sloughing off and being replaced. Layers
of smooth muscle function to move substances within the lumen, either to churn it (as in the stomach), increase the flow of
substances across the surface area of the epithelial cells for increased contact, or push it through the tract. Contractions force the
food forward in successive waves by peristalsis. Connective tissue supplies blood vessels, lymph vessels, and nerves to the wall
of the GI tract. The serosa, a thin layer of connective tissue that surrounds the entire tract, holds the digestive organs in place and
is continuous with the peritoneum, which lines the entire abdominal cavity.
Columbus City Schools
2015-2016
Tier Two:
Describe
Name
Explain
Tier Three:
Prefixes/Suffixes
AlimentCariCecChymDeciduFrenulGastrHepatHiatLinguPeriPylRectSorptVill-
70
Digestion begins when food enters the mouth, where chewing begins the process of mechanical breakdown. Three pairs of
salivary glands secrete saliva into the mouth, lubricating the food and initiating the process of chemical digestion. Digestive
enzymes secreted by the accessory organs and glands catalyze the breakdown of macromolecular polymers. The enzyme
amylase, present in the saliva, breaks down large starch molecules into maltose, a disaccharide made from two glucose subunits.
When a bolus of chewed food or liquid reaches the pharynx, the swallowing reflex is triggered, and a little flap of cartilaginous
tissue called the epiglottis moves to its down position and blocks the entrance to the respiratory tract. A muscular ring called a
sphincter relaxes, and food moves into the esophagus. Peristalsis moves the bolus down the esophagus into the stomach within
five to 10 seconds.
While the stomach churns the food, cells of its gastric glands secrete a variety of chemicals and enzymes that work chemically to
digest it. Hydrochloric acid (HCl) denatures proteins, kills most microorganisms that have been ingested, and disrupts the matrix
that holds many cells together in meat and plant tissue. The gastric glands secrete pepsinogen, an inactive digestive enzyme. The
acidic environment created by the HCl in the stomach causes the cleavage of pepsinogen, converting it to pepsin, an active
enzyme that cleaves peptide bonds between amino acids of protein chains. The gastric glands also secrete mucus and
bicarbonate, substances that protect the digestive juices from digesting the stomach lining. Contractions of the smooth muscles
surrounding the stomach move the contents, now called chyme, toward the pyloric sphincter, the opening to the small intestine.
The pyloric sphincter limits the amount of chyme that enters the duodenum, the first portion of the small intestine. In humans,
the duodenum is about 10 inches (25 cm), and the entire length of the small intestine is approximately 20 feet (6 m). The
pancreas, gallbladder, liver, and intestinal gland cells all discharge digestive enzymes and other substances into the duodenum.
By a combination of hormonal and neural mechanisms, distension of the intestine stimulates the pancreas to secrete pancreatic
amylase, lipases that digest lipids, and several types of proteases that digest proteins through a duct into the duodenum. Some
enzymes are secreted as zymogens, meaning they are secreted in an inactive form and must undergo a chemical change to
become active. The pancreas also secretes bicarbonate, a substance that buffers the acidic pH of chyme entering from the
stomach. The liver produces a solution called bile from bile salts, bile pigments, and cholesterol. The bile travels via hepatic ducts
to the gallbladder for storage until food enters the digestive tract, then flows through the common bile duct into the duodenum.
Bile contains no enzymes, but the bile salts help emulsify lipids to dissolve them in the fluids flowing through the GI tract. The
brush border, the epithelial lining of the duodenum, also secretes many digestive enzymes into the lumen, but other enzymes
including peptidases that hydrolyze peptides, disaccharidases that split disaccharides into monosaccharides, and a protease
called enteropeptidase remain attached to the surface of the brush border while the chyme and the enzymes it contains move
forward by peristalsis and other contractions. By the time the chyme reaches the end of the duodenum, enzymes have digested
most of the carbohydrates, proteins, lipids, and nucleic acids into monosaccharides, amino acids, fatty acids and glycerol, and
nucleotides, respectively.
The remaining two regions of the small intestine, the jejunum and the ileum, function mainly in absorption of nutrients. To
increase the surface area across which absorption occurs, the lining forms large circular folds that are covered with fingerlike
projections called villi. Microscopic extensions called microvilli extend from the villi, effectively increasing the surface area of the
internal lining and, consequently, the rate of absorption. Though the small intestine of an average adult human is about 20 feet (6
m) long, the surface area approaches 360 square yards (about 300 m2). Transport from the lumen of the small intestine across
the epithelial cells occurs by a combination of passive diffusion and active transport. Inside the epithelial cells, fatty acids and
glycerol molecules are reassembled into triglycerdes and combined with cholesterol molecules to form chylomicrons. Exocytosis
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moves the chylomicrons from the epithelial cells into lacteals, small ducts that drain into lymphatic vessels. The lymphatic
system eventually drains into blood circulation. The sugars, amino acids, nucleotides, and vitamins diffuse into tiny capillaries
that extend into each villus. The capillaries carry the nutrients to veins that converge into the hepatic portal vein, which
transports the absorbed materials to the liver.
Approximately 5.8 quarts (5.5 L) of food and beverages and 3.7 quarts (3.5 L) of secretions pass through the small intestine of a
human each day. The small intestine reabsorbs most of this in addition to various ions, but about 1.6 quarts (1.5 L) of chyme
moves on to the large intestine. After passing through the ileocecal valve, chyme enters a pouch called the cecum, from which the
appendix projects. Chyme then passes through the ascending colon, traverse colon, descending colon, sigmoid colon, and rectum,
where undigested material is stored until it is eliminated. The major function of the large intestine, which measures about five
feet (1.5 m), is to recover water as the chyme travels its roundabout route. The material solidifies as it moves through the tract,
sodium is absorbed, and potassium is added to the waste material. Billions of bacteria inhabit the large intestine and aid in
digestion of complex carbohydrates and proteins. Some also produce vitamins, such as vitamin K, that the human host absorbs,
and intestinal gas as a by-product of their metabolism. One voluntary and one involuntary sphincter control the movement of
waste from the rectum through the anus, the posterior opening of the digestive tract. Peristaltic contractions push the feces
toward the anus with the assistance of voluntary abdominal contractions. Constipation, the infrequent discharge of feces, results
in dry, hard bowel movements as a result of increased water reabsorption. Diarrhea is characterized by watery stools and results
when substances move through the large intestine too quickly, preventing the efficient reabsorption of water. Persistent
diarrhea can cause dehydration, a dangerous medical condition.
Hormones control the release of digestive enzymes, ensuring they are only secreted when food is present. The presence of amino
acids in the stomach or distension of the stomach stimulates cells in the gastric glands to release the hormone gastrin, which
travels through the bloodstream before acting back on the stomach. A pH below 1.5, indicating no food is present, inhibits the
release of gastrin. The protein hormone gastrin promotes acid release, and acid triggers somatostatin release, creating a negative
feedback loop that inhibits further gastric acid release, gastrin secretion, and pepsinogen secretion. When fatty acids and amino
acids are present, the duodenum secretes cholecystokinin (CCK), a hormone that causes the pancreas to secrete digestive
enzymes and the gallbladder to release bile. Enterogastrone, secreted by the duodenum, slows peristalsis when a diet rich in fats
is ingested, giving the intestine more time to digest the lipids. The duodenum also secretes secretin, a hormone that signals the
pancreas to release sodium bicarbonate to neutralize the acidic chyme.
Cullen, Katherine. "digestive system." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=ELS0068&SingleRecord=True>.
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I Can Statements
The students can…
□
□
□
□
□
□
□
□
Describe general functions of digestive system.
Name major organs of digestive system.
Explain how the contents of the alimentary canal are mixed and moved.
Describe the function and structures associated with the mouth.
Explain how the products of digestion are absorbed.
Explain control and movement of material through the alimentary canal.
Describe how digestive secretions are regulated.
Describe the mechanisms of swallowing, vomiting and defecating.
Misconceptions







Digestion starts in the stomach
Digestion ends in the stomach or large intestine.
The digestive system has two outlets – one for feces and one for urine.
The absorption of carbohydrates happens though out the digestive tract (mouth and stomach)
The acid really breaks down the carbohydrates into absorbable material (not enzymes)
Size doesn’t affect absorbability.
Confusion about where the breakdown of different nutrients is broken down.
http://theinnerhuman.weebly.com/misconceptions.html
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Instructional Strategies and Resources




BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
Columbus City Schools
2015-2016
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Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Respiratory System:
Essential Understandings
In humans, the respiratory system works with the circulatory system to obtain oxygen from the atmosphere and deliver it to the
tissues, where it is needed for cellular respiration (see figure below). The human respiratory and circulatory systems rely on a
form of transport known as bulk flow to bring volumes of air (with O2) into the lungs or volumes of blood (with O2) to the
tissues. For now, it is sufficient to know that bulk flow depends on differences in pressure and requires energy in the form of
ATP.
At all other points in this oxygen delivery system, however, oxygen transport is dependent on a passive (no ATP required) form
of transport known as diffusion. In this entry, we will focus on the process of diffusion and examine how the use of this process
impacts the design of the respiratory system.
Diffusion
Once atmospheric air has been brought to the respiratory surface of the lungs in very close proximity to the blood supply, oxygen
molecules move from the air into the blood. The form of transport used for this stage of oxygen transport is called diffusion.
Diffusion is the net movement of molecules from a region of higher concentration to one of lower
Once equilibrium has been achieved (i.e., once the concentrations of the molecule are the same in both regions), the rates of
movement between the two regions are equal and the overall net rate of diffusion is zero. The movement of molecules by
diffusion is a spontaneous process. Above absolute zero temperature (0 Kelvin) all molecules possess kinetic energy and are in
constant random motion. Molecules move and collide with other molecules and as the temperature of the medium increases, the
rate of these random movements and resulting collisions also increases.
Academic Vocabulary/
Language
Tier Two:
Identify
Explain
Name
Locate
Discus
Describe
List
Tier Three:
Prefixes/Suffixes
AlveolBronchCarcinCricEpiHemInhalPhrenTuber-
Fick's Law
There are many factors that influence the rate at which molecules, such as oxygen, diffuse from one area to another. Fick's law
describes the effects of these factors on the net rate of diffusion of a molecule (see figure below). Fick's law can be applied to the
rate at which oxygen diffuses from the atmosphere across the respiratory membrane and into the blood, and to the rate at which
carbon dioxide diffuses in the opposite direction.
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According to Fick's law, an increase in the surface area for gas exchange (i.e., the surface area of the lung) will increase the rate of
O2 diffusion. An individual who has a portion of lung tissue damaged because of cancer, for example, has a smaller than normal
surface for oxygen diffusion to occur and, as a consequence, a reduced rate of oxygen uptake.
The partial pressure gradient (P2 – P1) is the difference in partial pressures between the region with the higher PO2 (or P2) and
the region with the lower PO2 (or P1). The net diffusion of oxygen is always from the atmosphere (P2) to the blood (P1), because
the PO2 of the atmosphere is greater than the PO2 of blood. If P1 were equal to P2 (or P2 – P1= 0), there would be no net rate of
diffusion. For diffusion to occur, there must be a difference in the partial pressures between the two regions.
Several factors affect the rate of diffusion of oxygen into the lungs. Altitude affects the partial pressure of oxygen in the air. Fick's
law allows us to quantify the impact of high altitude, which has reduced atmospheric PO2, on O2 uptake by the body. For
example, at sea level, the partial pressure gradient for O2 diffusion into the blood may be 160 – 40, or 120 mm Hg. At the top of
Mount Everest, however, the gradient may be reduced to 53 – 40, or 13 mm Hg. This large drop in the partial pressure gradient
greatly reduces the rate at which oxygen enters the blood. Another factor that affects the diffusion rate is the thickness of the
diffusion barrier—in this case, the respiratory membrane. If this barrier increases in thickness, the rate of diffusion will
decrease.
Pulmonary edema is a condition in which fluid collects in the interstitium of the respiratory membrane, increasing the distance
that oxygen molecules must diffuse to reach the blood. Individuals suffering from pulmonary edema cannot take up oxygen from
the atmosphere as efficiently. One means of helping to counteract the reduced rate of diffusion is to increase the partial pressure
gradient by providing the patient with pure oxygen to breathe, effectively increasing PO2 levels from 160 to 760 mm Hg.
Diffusion is also temperature dependent. Because humans maintain a constant body temperature of 37°C (98.6°F), however,
diffusion at the lung surface is always at that temperature.
Connections
Fick's law governs the rate of diffusion of molecules like oxygen and carbon dioxide, the respiratory gases. Based on the
principles described in Fick's law, we might predict that a respiratory system would possess the following key features: (1) a
large surface area for gas exchange, (2) a short distance for oxygen diffusion, and (3) a design that maximizes the partial
pressure gradient. Because humans have high metabolic rates and, therefore, high requirements for oxygen, we would expect the
human respiratory system to incorporate these key design features in order to maximize the rate of oxygen uptake from the
atmosphere. We find that our predictions hold true. The human respiratory system has both an extensive surface area for gas
exchange (70 square meters) and an extremely thin barrier to gas diffusion in the alveoli.
Whittemore, Susan. "human respiratory system and the diffusion of gas molecules." Science Online. Facts On File, Inc.
Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=HBRES0004&SingleRecord=True>.
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I Can Statements
The students can…
□
□
□
□
□
□
□
□
□
□
Identify the general functions of the respiratory system.
Explain why respiration is necessary for cellular survival.
Name and describe the locations of the organs of the respiratory system.
Describe the functions of each organ of the respiratory system.
Explain how inspiration and expiration are accomplished.
List several non-respiratory air movements, and explain how each occurs.
Locate the respiratory areas, and explain control of normal breathing
Discuss how various factors affect breathing.
Explain how the blood transports oxygen and carbon dioxide.
Describe gas exchange in the pulmonary and systemic circuits
Misconceptions





We breathe in only oxygen and breathe out only carbon dioxide.
Inhaled air remains in the head.
Air is inhaled into the lungs, then exhaled, without links with the heart and circulatory system.
Inability to link the need for oxygen with the use of food.
Respiration is the same as breathing; the respiratory system is for carrying out respiration.
http://theinnerhuman.weebly.com/misconceptions.html
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Instructional Strategies and Resources




BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
Columbus City Schools
2015-2016
78
Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Urinary System:
Academic Vocabulary/
Language
Essential Understandings
The kidneys are the main excretory organs in vertebrate animals. In addition to excreting wastes, they produce some hormones
and help regulate water balance, osmolarity, ion balance, and pH levels. Occurring in pairs and situated in the lower back, the
mammalian kidneys contain complex systems of tubules and numerous capillaries. Each human kidney has about 1 million
nephrons, the functional units of the kidney. After the kidneys filter the blood to remove wastes and excess water and salts,
ureters transport the urine to the bladder for storage. When the bladder is full, the urine passes through the urethra to the
exterior of the body. In females the urethra exits near the vaginal opening, and in males the penis contains the urethra.
Tier Two:
Name
Describe
Explain
List
The mammalian kidneys consist of an outer renal cortex that surrounds the outer and inner renal medulla. The nephron consists
of several distinct regions that perform different functions in the production of urine. The Bowman's capsule envelopes the
glomerulus, the site of filtration. In mammals and birds, most nephrons (cortical nephrons) exist in the cortex and do not extend
into the medulla. In about 20 percent of nephrons (juxtamedullary nephrons), the proximal tubule carries the filtrate from the
cortex into the descending limb of the loop of Henle situated in the inner medulla. The ascending limb of the loop of Henle carries
the filtrate through the medulla back into the distal tubule, which drains into a collecting duct. Nephrons with this structure
allow for the production of concentrated urine to conserve water and are only found in mammals and birds. Cortical nephrons
have much shorter loops of Henle, and nephrons of other vertebrates do not have loops of Henle at all. Several nephrons empty
into a single collecting duct that leads to the renal pelvis and then the ureter.
Prefixes/Suffixes
Renal arteries supply blood to each kidney, and renal veins carry away the filtered blood. In the cortex, renal arteries diverge
into arterioles that branch out and associate closely with each individual nephron. As the blood enters a nephron through an
afferent arteriole, it first flows into a ball of capillaries called the glomerulus. As the blood leaves the glomerulus, the capillaries
converge into an efferent arteriole, which branches out again into peritubular capillaries that surround the tubules of the
nephron and into the vasa recta that extends down into the inner medulla region. The blood vessels are bathed in interstitial
fluid, as are the nephron tubules.
Tier Three:
Afcalyccortcystdetrusglomjuxtamictnephrpapillproxrentrigon
Nephron Function
The high pressure of blood in the afferent arterioles forces fluid through the porous capillaries of the glomerulus and across a
filtration membrane into the lumen of the Bowman's capsule. The filtrate in the Bowman's capsule contains water, salts,
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bicarbonate ions (HCO3-), hydrogen ions (H+), urea, glucose, amino acids, and certain drugs. Blood cells and large molecules
such as proteins cannot penetrate and remain in the blood vessels. Reabsorption and secretion both occur through a transport
epithelium in the proximal tubule via a combination of active transport, cotransport, facilitated diffusion, and simple diffusion.
Transport epithelial cells help maintain blood pH levels by secreting excess H+ into the filtrate in addition to synthesizing
ammonia, which passively diffuses into the filtrate, preventing it from becoming too acidic. Sodium ions (Na+) and chloride ions
(Cl-) from the filtrate diffuse into the transport epithelial cells, which actively transport the Na+ into the interstitial fluid. Cl- ions
follow to balance the charge gradient, and water follows by osmosis. The salts and water then move back into blood circulation
via the peritubular capillaries. The proximal tubule is also the site for reabsoprtion of HCO3-, potassium ions (K+), and nutrients
such as sugars and amino acids. Some drugs or other toxins pass from the peritubular capillaries to the interstitial fluid, and the
transport epithelium secretes them into the urine.
As the filtrate travels down the descending loop of Henle, reabsoprtion of water continues. The concentration of solutes in the
interstitial fluid increases gradually from the cortex to the inner medulla of the kidney. The transport epithelium of the
descending loop of Henle is not permeable to salts; thus only water moves out, resulting in significant concentration of the
filtrate. In contrast, the ascending loop of Henle is permeable to salt but not water. In the lower portion of the ascending loop,
salts diffuse out of the filtrate into the interstitial fluid. This helps maintain the solute concentration gradient between the cortex
and the medulla. By the time the filtrate reaches the upper portion of the ascending loop, the transport epithelium must actively
transport salts into the interstitial fluid. Because the ascending loop of Henle is not permeable to water, the result is dilution of
the filtrate. The distal loop plays an important role in regulating pH levels and salt concentrations. The transport epithelium
secretes H+ and K+ into the filtrate and reabsorbs HCO3-, Na+, and Cl-. Water moves out by osmosis as the filtrate travels
through the distal tube and down the collecting duct, concentrating the filtrate once again. Under hormonal influences, the
transport epithelium of the collecting duct actively reabsorbs varying amounts of Na+ and Cl-, depending on how hydrated or
dehydrated a person is. As the filtrate approaches the end of the collecting duct, the transport epithelium becomes permeable to
urea. Though most urea is destined for excretion, its concentration is so high in the filtrate at this point that some diffuses out,
contributing to the high solute concentration in the medulla. The high levels of solute in the medulla allow mammals to conserve
water very efficiently, resulting in the production of hyperosmotic urine, urine that is much more concentrated than body fluids.
Urine drains from the collecting duct, into the renal pelvis, and down the ureters to the bladder.
The average human bladder can hold approximately one pint (close to 500 mL) of urine. As the volume increases, the bladder
wall stretches, resulting in micturition, or emptying of the bladder. Stretch receptors communicate the information that the
bladder is full to the nervous system, which responds by sending signals that relax the skeletal muscles around the urinary
sphincter, opening it and allowing the fluid to drain out. Contractions of smooth muscle surrounding the bladder help force the
urine out. In infants, micturition is a reflex, but as one grows older, the ability to inhibit micturition voluntarily develops.
Cullen, Katherine. "excretory system." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=ELS0092&SingleRecord=True>.
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I Can Statements
The students can…
□
□
□
□
□
□
□
□
□
□
Name the organs and general functions of the urinary system.
Describe the location, structure, blood flow and functions of the kidneys.
Describe the parts and function of a nephron.
Explain urine concentration/composition.
Describe the structures, of the ureters, urinary bladder and urethra.
Explain how the micturition occurs and how it’s controlled.
List routes by which water enters and leaves the body.
Explain the regulation of water input and water output.
List the routes by which electrolytes enter and leave the body.
Explain the regulation of the input and output of electrolytes.
Instructional Strategies and Resources




BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Columbus City Schools
2015-2016
81
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
Columbus City Schools
2015-2016
82
Ohio’s New Learning Standards - Clear Learning Targets
Anatomy and Physiology
Anatomy and Physiology
Reproductive System:
Models of the atom, ions, Isotopes
Essential Understandings
Human beings are sexually dimorphic, meaning separate male and female forms exist. Males produce haploid gametes called
spermatozoa (sperm), and females produce ova (eggs). During sexual intercourse, the man deposits sperm into the female
reproductive tract. If one sperm cell finds and penetrates an egg cell, a zygote is formed. The zygote develops into an embryo,
then a fetus, and, after nine months, a baby is born.
Establishment of an individual's genetic or chromosomal sex occurs at the moment of fertilization, when a spermatozoon
penetrates an egg cell. Normal diploid human cells have 46 chromosomes, 22 pairs of autosomes (nonsex chromosomes) and
one pair of sex chromosomes. The sex chromosomes are called the X and the Y chromosomes, and the combination of these
determines gender. Females can contribute only X's when making egg cells, and males can contribute either an X or a Y. If a
sperm cell containing an X chromosome fertilizes an egg, the offspring will be XX, a chromosomal female. If a sperm cell
containing a Y chromosome fertilizes an egg cell, the offspring will be XY, a chromosomal male.
Biological sex refers to the type of specialized sex organs a person possesses: ovaries for females or testes for males. The
physiological decision that determines the biological sex occurs during early embryonic development at approximately the
seventh week of gestation, when the specialized sex organs develop. In most situations a person's chromosomal and biological
sex match, but chromosomal aberrations or molecular mutations can result in discordance. Determination of a newborn's gender
depends on the presence of characteristic external genitalia at birth, but humans do not sexually mature until adolescence.
During puberty, a person completes the transition from sexual immaturity to becoming a fertile adult. Secondary sexual
characteristics appear, the external genitalia enlarge and develop, and, internally, the gonads mature and begin to secrete
hormones that complete the process of sexual maturation and produce gametes capable of participating in fertilization.
Adolescent females experience menarche, the onset of menstrual cycling, in preparation for a possible pregnancy.
Male Reproductive System
A sexually mature, fertile male must produce viable gametes, sperm cells, and successfully deliver them into the female
reproductive tract. The male reproductive structures include the testes, the epididymides (singular, epididymis), vas deferentia
(singular, vas deferens), urethra, seminal vesicles, prostate gland, bulbourethral glands, scrotum, and penis.
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Describe
Explain
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The primary sex organs in males are the testes, or testicles, a pair of egg-shaped organs located in an external sac called the
scrotum. The testes produce steroid hormones such as testosterone and make sperm. Testosterone is the main male sex
hormone that stimulates the development of male secondary sexual characteristics, such as increased muscle mass, the growth
of facial and pubic hair, and a deeper voice, and maintains testicular function after puberty. The production of sperm requires
temperatures around 93°F (33.9°C), a fewer degrees lower than normal body temperature of 98.6°F (37°C). Because of this, near
the time of birth, the testes descend from the pelvic cavity into the scrotal sac where they are kept slightly cooler than inside the
body. Under cold conditions, contraction of muscles around the scrotal sac draws the testes closer to the body to warm them and
to decrease the surface area through which heat dissipates.
Each testis consists of approximately 250 lobules or compartments divided by septa made of connective tissue. Each contains
one to three convoluted seminiferous tubules, the site for sperm production, a process called spermatogenesis. Stretched out, a
single seminiferous tubule measures between 12 and 28 inches (30 and 70 cm) in length. The epithelial lining of the tubules
contains two types of cells: Sertoli cells and developing sperm cells. Sertoli cells provide nourishment for the germ cells, play a
role in the hormonal control of spermatogenesis, and phagocytose degraded germ cells. The base of a Sertoli cell lies against the
basement membrane, and the cell extends outward toward the center of the tubule. The heads of maturing sperm are embedded
in Sertoli cells, while the tails hang in the lumen of the tubule. Leydig cells, or interstitial cells, are the cells in the testes that
produce steroid hormones. They are positioned within the lobules in the spaces between the seminiferous tubules, along with
blood vessels.
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Spermatogenesis occurs inside the lining of the seminiferous tubules. The process begins with spermatogonia, undifferentiated
germ cells that constantly undergo mitosis, cell division of a diploid parent cell to form two diploid daughter cells. During
mitosis, each chromosome duplicates itself and one member of each identical pair passes to a daughter cell, resulting in progeny
identical to the parent cell; thus, mitosis constantly replenishes the supply of spermatogonia. Spermatogenesis involves meiosis,
a two-staged form of cell division that results in the formation of haploid daughter cells, cells that only contain half of the diploid
number of chromosomes and that can fuse with a gamete made by the opposite sex to form a diploid zygote during fertilization.
Spermatogonial cells that have begun meiotic division are called primary spermatocytes. During the first stage of meiosis, one
spermatogonium gives rise to two haploid secondary spermatocytes, but the chromosomes are still duplicated. In other words,
only 23 chromosomes are present in each cell, but each chromosome is still linked physically to an identical copy of itself. The
second meiotic division separates the identical copies of each chromosome, resulting in four haploid spermatids. The spermatids
then undergo spermiogenesis, a process by which they differentiate into mature sperm. In humans, the complete transformation
of one spermatogonial cell into four mature sperm cells takes about 64–74 days, and every day, the testes produce
approximately 200 million new sperm. When viewed in cross section, one can observe the progression of stages of
spermatogenesis and spermiogenesis that occurs beginning at the basement membrane of the tubule and looking inward toward
the center or lumen of the seminiferous tubule.
A mature sperm cell has three parts, a head, a middle section, and a tail. The head contains the nucleus holding the 23
chromosomes. A cap called the acrosome, a pocket full of enzymes that aids in the penetration of an egg cell during fertilization,
is present on one end of the head. The midsection connects the head to the tail and houses mitochondria that supply energy
needed for movement. The tail, or flagellum, of the sperm contains microtubules that slide past one another, causing a wavelike
motion that propels the sperm forward.
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After their release into the lumen of the seminiferous tubules, mature sperm travel to the rete testis, a tubular network that
empties into the efferent ductules, ciliated tubules that lead out of the testis. The epididymis is a comma-shaped structure
located on the posterior side of the testis that stores sperm and secretes substances that help the sperm mature further. The vas
deferens, a long tubular structure, emerges from the end of each epididymis, extends 18 inches (45 cm) into the abdominal
cavity, loops over the bladder, and enlarges to form an ampulla, a reservoir for the sperm. The ampulla leads to a short
ejaculatory duct that connects to the urethra, which extends approximately eight inches (about 20 cm) from the urinary bladder
to the end of the penis. Both urine and semen pass through the urethra to exit the body, but not at the same time. A mechanism
exists that blocks the flow of urine during ejaculation, when rhythmic contractions force sperm out of the urethral opening.
During sperm transport, different sex accessory glands secrete substances that make up the seminal plasma, the fluid that carries
the sperm. The majority of the volume of seminal plasma comes from paired seminal vesicles that lie at the base of the bladder
and secrete a thick alkaline fluid containing the sugar fructose. Short ejaculatory ducts carry contents from the seminal vesicles
to the ampulla of the vas deferens. The prostate gland is a doughnut-shaped structure that is located below the bladder and
surrounds the upper portion of the urethra. Alkaline fluid flows from the prostate through several tiny ducts that empty into the
urethra. Another pair of glands, the pea-sized bulbourethral glands (also called Cowper's glands), lie at the base of the penis and
secrete mucous that lubricates the urethra, facilitating the flow of semen during ejaculation.
The penis is the copulatory organ of the male, meaning it functions in getting the sperm from the duct system of the male
reproductive tract into the female reproductive tract, a requirement for internal fertilization. Three columns of erectile tissue
run along the length of the penis, in addition to blood vessels and nerves. The two columns on the sides of the penis are called
corpora cavernosa, and the third column, the corpus spongiosum surrounds the urethra on the ventral side. At the end of the
penis, the corpus spongiosum forms a cap, the glans penis, that is covered by the prepuce, or foreskin. Circumcision is the
surgical removal of the foreskin, a practice usually performed for religious or cultural rather than medical reasons.
When an adult male becomes sexually aroused, the spongy erectile tissue fills with blood, becoming engorged and stiffening the
penis. The purpose of an erection is to allow the male to insert his penis into the female vagina during intercourse. Continued
stimulation leads to emission, the accumulation of sperm and seminal plasma in the urethra. Peristalsis, rhythmic waves of
contractions of smooth muscles surrounding the reproductive ducts, transports the sperm, which is expelled from the distal end
of the penis during ejaculation. Approximately 300–400 million sperm cells in about 0.7 teaspoons (3.5 mL) of semen are ejected
during ejaculation, but only one sperm cell is necessary for conception to occur. Once a male has deposited his sperm into the
female reproductive tract, his role in reproduction is complete.
Female Reproductive System
The female reproductive system must not only make gametes, but also house the sperm for up to two days, transport the early
embryo to the uterus, implant it, nourish the embryo and fetus during the nine months of pregnancy, deliver the baby, and
produce and secrete milk to feed the newborn. The female reproductive organs include the ovaries, uterine tubes, uterus, vagina,
external genitalia, and mammary glands.
A group of ligaments supports the internal abdominal reproductive organs and holds them in place. Ovaries are the primary
reproductive organs in females. The paired structures, located in the pelvic cavity on either side of the uterus, produce ova and
secrete the female steroid sex hormones estrogen and progesterone. A thin surface epithelium covers the ovarian cortex, the
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portion of the ovary that is made of dense connective tissue and contains the primary germ cells, the oogonia. Internal to the
cortex is the ovarian medulla, the region containing the blood vessels, lymphatic vessels, and nerves.
Oogenesis, the production of female gametes, begins during fetal development. After initiating meiosis, an oogonium becomes a
primary oocyte. Meiosis halts in the middle of the first meiotic division and does not resume until after puberty. In order to be
fertilized, the immature germ cell must resume oogenesis and be released into the female reproductive tract. Following sexual
maturation, the process of ovulation, the release of a mature ovum from an ovary, occurs approximately once per month. Just
prior to ovulation, the primary oocyte completes the first meiotic division, resulting in a haploid secondary oocyte and a polar
body. The majority of the cytoplasm, including organelles such as the mitochondria, remains with the secondary oocyte, and the
polar body acts mainly as a repository for extra genetic material. The polar body either degenerates or completes the second
stage of meiosis, forming two polar bodies. The secondary oocyte initiates the second meiotic division but stops before the
process is complete until fertilization occurs.
A layer of granulosa cells surrounds the primary oocytes, forming structures called primordial follicles that lie around the edge
of the ovarian cortex. After puberty, some of the primordial follicles develop into primary follicles, and, on average, every 28
days some of the primary follicles mature into secondary follicles. At this stage, the follicles contain a large, fluid-filled antrum,
and the oocyte rests to one side within a mass of granulosa cells called cumulus cells. A clear membrane called the zona pellucida
lies between the oocyte and the innermost layer of granulosa cells called the corona radiata. The theca, the capsule that
surrounds the follicle, contains the cells that produce ovarian hormones.
Female babies are born with all the immature germ cells they will ever have. By the fourth month of development, the ovaries
contain about 5 million primary germ cells, or oogonia. The number of follicles decreases to about 2 million prior to birth, and
about 200,000–400,000 by puberty. Only 400 will ever mature into ova. The process of follicular degeneration is called atresia,
and it can occur at any stage of follicular development. The most mature follicles, Graafian follicles, protrude as lumps from the
ovary. Only one normally reaches this stage each month. During ovulation, the follicle ruptures, releasing the oocyte and its
surrounding mass of cumulus cells into the abdominal cavity. If more than one follicle fully matures simultaneously, more than
one can be fertilized, and a multiple birth can result.
The infundibulum, a funnel-like structure at the opening of each oviduct, also called fallopian tube or uterine tube, surrounds a
large portion of the ovary and accepts the ovum at the ostium, the opening. Extensions called fimbriae embrace the ovaries and
help ensure that the egg actually enters the uterine tubes rather than remain loose in the peritoneal cavity. Muscular tissue that
encircles the oviducts contracts to help move the ovum toward the uterus. In addition, the internal lining of the oviducts secretes
mucous and has cilia that beat to aid in transport. Fertilization, the fusion of a haploid sperm cell with a haploid egg cell to form a
diploid zygote, normally occurs in the oviducts. The zygote begins rapidly dividing by mitosis, while continuing to travel toward
the uterus.
The uterus is a thick, muscular organ with dimensions of approximately 3 × 2 × 1 inches (7.5 × 5 × 1.75 cm). The uterine fundus
is the region where the oviducts join on either side near the top. The cervix is a narrower region adjacent to the vagina, the canal
that leads to the vestibule, the opening to the exterior environment. The uterus consists of three layers of tissue: the thin outer
membrane called the perimetrium, the thick layer of smooth muscle called the myometrium, and the innermost layer, the
endometrium, in which a developing embryo implants. In nonpregnant women, the structure of the endometrium changes in
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response to hormonal cues, leading to a cyclical series of monthly physiological changes, the menstrual cycle. Prior to ovulation,
the endometrium proliferates in preparation for receiving a developing embryo, but, in the absence of pregnancy, the uterus
discharges blood, secretions, and endometrial tissue in a process called menstruation, and a new cycle begins.
The vagina serves as a portal for the exit of menstrual discharge, as a receptacle for deposition of semen from the penis during
sexual intercourse, and as part of the birth canal during parturition. The epithelial cells that line the inner region secrete mucous
that lubricates the vagina. The muscular vaginal walls can stretch to accommodate the penis during coitus and during childbirth.
Menstrual Cycle
The ovaries and the uterus both play key roles in the female reproductive system, but to reproduce successfully, they need to
work together to coordinate the timing of their functions. If ovulation occurred too close to menstruation, the uterine lining
would not be prepared to receive an embryo for implantation. Hormones regulate the cycle of events that happen in the ovary,
the ovarian cycle, with the menstrual (uterine) cycle.
The ovarian cycle has two phases, the follicular and the luteal phase. The cycle begins when the hypothalamus secretes
gonadotropin releasing hormone (GnRH), which in turn stimulates the anterior pituitary gland to secrete small amounts of
follicle-stimulating hormone (FSH) and luteinizing hormone (LH). As its name suggests, FSH stimulates the development of up to
25 follicles in the ovary. The follicular cells are the cells responsible for the production and secretion of estrogen, so as the
follicles grow, the circulating levels of estrogen increase. During most of the follicular phase, the levels of estrogen are low, and
low levels of estrogen inhibit the anterior pituitary from releasing more FSH and LH. In addition, developing follicular cells
secrete inhibin, a protein that inhibits FSH secretion. As the follicular cells secrete increasing levels of estrogen, the
hypothalamus secretes more GnRH. In response, the levels of LH and FSH rise sharply, an event termed the LH surge. As
follicular cells develop, their sensitivity to LH also increases due to an increase in the number of LH receptors. Usually, only one
follicle fully matures to the Graafian stage. In response to the LH surge, the primary oocyte of the mature follicle completes the
first meiotic division and a large fluid-filled sac develops in the follicle and finally ruptures, causing ovulation of the secondary
oocyte about one day later. Ovulation occurs on or near day 14 of a 28-day cycle and marks the end of the follicular phase.
LH induces the transformation of the ruptured follicle into a corpus luteum, hence the name luteal phase for the second phase of
the ovarian cycle. The remaining granulosa cells of the corpus luteun secrete increased levels of progesterone and some
estrogen. The combined high levels of these two hormones inhibit the hypothalamic release of GnRH, and they also decrease the
number of GnRH receptors in the anterior pituitary. Together, these events cause the levels of LH and FSH to decrease to very
low levels. In the absence of pregnancy, the corpus luteum disintegrates, so the production of estrogen and progesterone
declines sharply. The return of low levels of estrogen and progesterone remove the inhibitory effect of the combined high levels
of those hormones on the hypothalamus, and GnRH is released. The anterior pituitary responds by releasing FSH, which
stimulates the development of a new group of follicles in the ovary, completing the cycle and initiating another one.
Meanwhile, the uterus must prepare for possible implantation in case fertilization of the ovulated oocyte occurs. Estrogen and
progesterone both affect physiological events in the uterus. The onset of menstruation (a woman's period) marks the first day of
a new ovarian cycle and the menstrual flow phase of the uterine cycle. The increasing levels of estrogen produced by the
developing follicular cells in the ovary cause the endometrial lining to proliferate, thus the next phase of the uterine cycle is
called the proliferative phase. Cells rapidly divide to replace the cells lost during menstruation, forming spiral-shaped uterine
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glands. Spiral arteries supply a rich source of nutrients to the endometrial cells. After ovulation, when the corpus luteum forms,
the progesterone it secretes induces the secretory phase of the uterine cycle, and the uterine glands thicken and start to secrete a
fluid rich in the carbohydrate glycogen. By day 21 of the menstrual cycle, the uterine lining is suitable for accepting an embryo
for implantation. In the absence of pregnancy, as the corpus luteum disintegrates and the levels of estrogen and progesterone
both drop near the end of the luteal phase, the spiral arteries that supply the uterine glands with nutrients constrict. Without
oxygen, the cells of the spiral glands die and the functional layer of the uterine lining sloughs off, and the menstrual fluid flows
out of the uterus through the cervix and vagina. A new cycle begins.
Pregnancy, Birth, and Lactation
After a male deposits sperm into the vagina of a female, the sperm swim through the cervix and uterus into the oviducts,
sometimes aided by contractions of the uterus caused by prostaglandins in the semen and oxytocin released from the female
posterior pituitary gland. The environment of the female reproductive tract is acidic, but the alkaline character of the semen
keeps the sperm alive during their journey. Ejaculated sperm cannot penetrate the zona pellucida of the ovum until they undergo
a process called capacitation, which is stimulated by conditions in the female reproductive tract. Acrosomal enzymes are
released, allowing penetration of the cervical mucous, the cumulus mass cells, and the oocyte cell membrane. Sperm have 24
hours after ovulation to reach an egg, but sperm themselves can survive for up to six days in the female tract. After a sperm
penetrates the secondary oocyte, the second meiotic division resumes, forming an ootid and another polar body. The nuclear
contents of the sperm cell fuse with the nuclear contents of the ovum, regenerating the diploid state and forming a zygote.
Biochemical changes prevent more than one sperm cell from fertilizing an ovum.
The zygote undergoes a series of rapid cell divisions called cleavage. Within one week after fertilization, the embryo has traveled
as far as the uterus and has developed into a blastocyst, a sphere of cells with a hollow interior. The embryo settles into the
endometrial lining, which is ideal for implantation during the secretory phase of the uterine cycle. The trophoblast, the outer
layer of the embryo, secretes a hormone called human chrorionic gonadotropin that travels via blood circulation to the ovaries,
where it acts to maintain the corpus luteum, which would start disintegrating in the absence of a pregnancy. The corpus luteum
continues to secrete progesterone and estrogen, hormones necessary for maintenance of the uterine lining throughout the
pregnancy, and the mother ceases to ovulate or have menstrual cycles until she is no longer pregnant. After the placenta
develops, it begins to produce estrogen and progesterone, and, at about three months, it produces sufficient quantities of the
hormones without assistance from the corpus luteum.
Gestation of a human fetus takes nine months, divided into three trimesters. After implantation, the endometrium grows over
the blastocyst. Membranes that protect the developing baby also develop. The amnion encloses the entire embryo, and the
chorion helps the trophoblast to form the placenta, a disk-shaped organ through which diffusion occurs. The placenta is very
vascular, and without any direct mixing of maternal and fetal blood, oxygen and nutrients from maternal circulation diffuse out
of maternal vessels into fetal vessels. Carbon dioxide and waste products diffuse out of fetal circulation, and maternal vessels
carry them away. Other substances such as drugs, alcohol, and some pathogens can diffuse across the placenta and enter fetal
circulation, thus the mother must be vigilant about her health. An umbilical cord connects the placenta to the fetus. Two
umbilical arteries bring fetal blood to the placenta, and one umbilical vein carries blood from the placenta back to the fetus.
Organogenesis, the development of body organs, occurs mainly during the first trimester. By the end of the first trimester, the
embryo is called a fetus.
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During the second trimester, the fetus becomes distinctly recognizable as a human, and even develops fine structures such as
fingernails and eyebrows. The uterus grows large enough to form an obvious protrusion from the lower abdomen. The corpus
luteum disintegrates and the placenta completely assumes the job of producing progesterone.
The last trimester is characterized by rapid fetal weight gain. The large uterus compresses the mother's internal organs and can
cause heartburn, constipation, frequent urination, and back pain. After approximately 40 weeks from the first day of the last
menstrual period, the fetus is ready for life outside of the mother's womb.
Fetal Development
The mechanisms that initiate labor are not fully understood but involve numerous hormones. Estrogen levels rise significantly
during the last trimester and, as a result, the numbers of oxytocin receptors on the uterus increase. Made by the fetus and the
mother's pituitary, the hormone oxytocin induces uterine contractions and stimulates the placenta to secrete prostaglandins,
which also stimulate contractions. The stress associated with labor causes the release of even more oxytocin, forming a positive
feedback loop that ends after birth, or parturition. Labor includes all the physical activities that lead up to birth. During the first
stage of labor, the cervix effaces (thins out) and dilates (opens up) wide enough to allow passage of the baby. The uterus
contracts in a rhythmic manner to force the baby down and out through the birth canal. The mother assists by bearing down to
push the baby out. After the baby is born and the umbilical cord is cut, the mother still must deliver the placenta. Situations that
are dangerous for the mother or the fetus sometimes necessitate a cesarean section, the delivery of a fetus by surgical incision of
the abdominal walls.
As mammals, human mothers have the ability to produce and secrete milk from their breast tissue. During pregnancy, the
breasts enlarge, and the duct systems and secretory units of the breast tissue mature. The drop in progesterone levels following
parturition leads to the secretion of the hormone prolactin from the anterior pituitary. Prolactin stimulates milk production by
the mammary glands in the breasts, but it takes a few days after birth for milk production to begin. Until that time, the mammary
glands secrete colostrum, a fluid rich in antibodies and nutrients. The antibodies help the newborn fight infection while his or
her immune system is developing. When the baby suckles at the nipple, prolactin is released from the anterior pituitary and
oxytocin is released from the posterior pituitary. Oxytocin stimulates the release of milk from the breast. Breast milk contains all
the nutrients essential for a newborn during its first year of life. As long as a mother continues to breastfeed, the suckling will
stimulate the continued production and secretion of more milk.
Cullen, Katherine. "human reproduction." Science Online. Facts On File, Inc. Web. 18 Aug. 2015.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=ELS0121&SingleRecord=True>.
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I Can Statements
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Columbus City Schools
Describe function(s) of each part of the male reproductive system.
Outline the process of spermatogenesis.
Describe semen production; exit from body
Explain how hormones control the activities of the male reproductive organs and the development of secondary sex
characteristics
Describe function(s) of each part of the female reproductive system.
Outline process of oogenesis
Explain how hormones control the activities of the female reproductive organs and the development of secondary sex
characteristics
Describe major events of female reproductive cycle.
Describe fertilization.
List and provide major events of cleavage.
Describe implantation.
Discuss hormonal changes in body during pregnancy
Explain primary germ layers origin, list structures each layer produces.
Describe major events of embryonic development.
Describe formation and function of placenta.
Define fetus, describe major events of fetal development.
Trace path of blood through the fetal cardiovascular system.
Explain role of hormones in milk production
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Instructional Strategies and Resources
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BioDigital Human offers interactive 3D models of human anatomy. You can turn on and off different views according to which body systems you want to
view. The models can be rotated 360 degrees and the labels have an audio play-back option. The video below offers an overview of BioDigital Human. If
you are going to use BioDigital Human in your classroom, there are two things to keep in mind. First, the models are 100% anatomically correct. Second,
you do need to have your browser updated to the latest version possible to experience all that BioDigital Human has to offer.
https://www.biodigital.com/
Healthline Body Maps provides interactive three dimensional models for learning about human anatomy. Body Maps has male and female models. The
models have eight layer views, from skin to skeletal, that you can select. You can hold your mouse pointer over any part of the model to view a body
part's name and then zoom to more detailed information. For example, if I place my mouse on the stomach I can then click through for a more detailed
view and to see how the stomach is connected to other body parts. To rotate the model just click and drag the model to the left or right.
http://www.healthline.com/human-body-maps/
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs
and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can
build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems. Build a Body also has a case study
menu in which students can read about diseases, disorders, and and other concerns that affect the human body. In each case study students are given a
short description of the concern followed by a question that they should be able to answer after completing the Build a Body activity.
http://www.spongelab.com/game_pages/BAB.cfm
The University of Pennsylvania Health System provides nearly 200 video animations and explanations of injuries, diseases, and body systems. The
animations, like this one of a balloon angioplasty, are concise which makes them good for general reference purposes.
http://www.pennmedicine.org/health_info/animationplayer/
Career Connections
http://www.innerbody.com/careers-in-health.html
Sample AIR Test Question Not applicable for this course
Prior Knowledge
Future Knowledge
No prior information on this topic has been taught.
No further information on this topic will be taught.
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