Download Chapter 2: Body Structure Chapter Objectives

Chapter 2: Body Structure
Chapter Objectives
On completion of this chapter participant will be able to:
1.
2.
3.
4.
5.
6.
7.
8.
Differentiate between anatomy and physiology.
Describe the levels of organization of the body.
Identify terms used to describe cells, tissue, and glands.
Identify body planes, directions and cavities.
Define the roots that apply to the body systems.
Recognize, define, spell, and pronounce terms related to procedures of glands
and tissue.
Describe the major medical specialties as they pertain to the body systems.
Complete the review exercise at the end of the chapter.
This chapter will introduce you to some of the basic concepts that are related to the
study of the human body. This will prepare you to consider the roots that apply to the
various body systems.
Anatomy and Physiology
The terms “anatomy” and “physiology” are terms that will be referred to throughout this
text, and their meaning is the same regardless of the body system being discussed.
Anatomy is the study of the parts or structures of the body, while physiology is the
study of how the body parts work. Other terms which refer to the structure and function
of the body systems are outlined in table 2.1.
Table 2.1
Terms related to anatomy and physiology
Term
Meaning
Pathophysiology
(path-oh-fiz-ee-ol-oh-jee)
Study of changes in the function of a
body system caused by disease.
Pathology (pah-thol-oh-jee)
Study of the nature and cause of
abnormal conditions.
Etiology (ee-tee-ol-oh-jee)
Study of the cause of a disease.
Body Organization
All living things consist of very small structures called cells. These cells perform a
variety of functions in the body. Regardless of their function they are all similar in their
structure. The next level of organization is tissue, which is the grouping of a number of
cells together to form something that is larger and more complex than a single cell: e.g.
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muscle, bone. A number of tissues then combine to form organs, such as the heart,
lungs, brain, etc. All of the organ systems we have go together to form the human
body.
The Cell
The cell is the basic structural unit of the body. Each cell is specialized and when these
specialized cells are grouped together they form the tissue of the body. The cell is
made up of:
Protoplasm: (material that makes up the cell) This includes the:
Û Cell Membrane that is the structure that surrounds and protects
the cell.
Û Cytoplasm is material located inside the cell that is not part of
the nucleus.
Û Nucleus is the powerhouse of the cell. It sustains the life of the
cell and because of the chromosomes it contains allows the cell
to reproduce.
Cell Membrane
Nucleus
Cytoplasm
Figure
Tissue
Tissue is a group or layer of similarly specialized cells that join together to perform
certain specific functions. The study of the structure, composition and function of tissue
is referred to as histology (hiss-tol-oh-jee). The root hist means tissue and the suffix logy means study of.
The types of tissue that you find in the body are:
Û
Epithelial (ep-ih-thee-lee-al)
Covers both the internal and external surfaces of the body.
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Û
Table 2.2
Connective
Holds the organs of the body in place and binds all parts of the
body together. Types of connective tissue are: bone, cartilage and
adipose or “fat”.
Medical Terms Related to Tissue
Term
Meaning
Aplasia (ah-play-zee-ah)
Lack of development of tissue or an
organ. (Prefix “a” means without)
Hypoplasia (high-poh-play-zee-ah)
Incomplete development of tissue or an
organ. (Prefix “hypo” means below,
decreased or deficient)
Hyperplasia (high-per-play-zee-ah)
Abnormal increase in the number of
normal cells in a tissue. (Prefix “hyper”
means above, increased or excessive)
Dysplasia (dis-play-see-ah)
Abnormal development or growth of cells.
(Prefix “dys” means difficult, painful
or bad)
Anaplasia (an-ah-play-zee-ah)
Change in the structure of cells and their
orientation to each other. (Prefix “ana”
means without)
Glands
A gland is a group of specialized cells that secrete a material used somewhere else in
the body. The root for gland is aden/o. There are two types of glands in the body.
Exocrine (eck-soh-krin) glands secrete their substances into ducts that take it to the
area of the body where it will be used. An example of an exocrine gland is the sweat
gland. Endocrine (en-doh-krin) glands don’t have ducts and their secretions flow
directly into the blood stream. The blood transports it to the area of the body where it
will be used. An example of an endocrine gland is the thyroid gland. We have one
gland in the body, the pancreas, which functions both as an exocrine and an endocrine
gland.
Organs and Body Systems
There are twelve organ systems (often referred to as body systems) found in the human
body. These systems work together to perform all the necessary functions of life. The
table on page 14 outlines all the body systems and their functions. Some of the
common roots that apply to that system are also included. A more detailed list of roots
for the system will appear in the chapter where the body system is discussed.
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Table 2.3
Body Systems
Body System
Common Roots
Major Functions
Skeletal System
Bones oste/o
Joints arthr/o
Cartilage chondr/o
Support and shape the body.
Protection, storage of minerals, and
production of blood cells.
Muscular System
Muscles my/o
Fascia fasci/o
Tendons ten/o, tend/o, tendin/o
Movement of the body. Holds the
body erect and generates body
heat.
Cardiovascular System
Heart cardi/o
Arteries arteri/o
Veins ven/o, phleb/o
Blood hem/o, hemat/o
Carries food and needed oxygen to
body cells.
Lymphatic and
Immune System
Lymph nodes & vessels lymph/o
Tonsils tonsill/o
Spleen splen/o
Provide nutrients and removes
waste from the tissue. Protects the
body from harmful substances.
Respiratory System
Nose nas/o
Pharynx pharyng/o
Trachea trache/o
Larynx laryng/o
Lungs pneum/o, pneumon/o
Brings oxygen into the body for use
by the cells and removes the waste
product carbon dioxide.
Digestive System
Mouth or/o
Esophagus esophag/o
Stomach gastr/o
Small intestine enter/o
Large intestine col/o
Liver hepat/o
Pancreas pancreat/o
Digestion of food and absorption of
the nutrients needed for life.
Elimination of solid body wastes.
Urinary System
Kidney nephr/o, ren/o
Ureters ureter/o
Urinary bladder cyst/o, vesic/o
Urethra urethr/o
Filters blood to remove waste
products and maintain the right fluid
balance in the body
Nervous System
Nerves neur/o
Brain encephal/o, cerebr/o
Spinal cord myel/o
Coordinating mechanism within the
body. Transmits messages
throughout the body
Integumentary System
Skin derm/o, dermat/o,
cutane/o
Protection of the body. Controls
temperature and water regulation.
Endocrine System
Adrenal adren/o
Pituitary pituit/o
Thyroid thyroid/o
Integrates body functions and
growth.
Reproductive System
Testes orch/o, orchid/o
Ovaries oophor/o, ovari/o
Production of new life.
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Medical Specialities
For each of the major body systems there is a medical term to describe that special
branch of medicine and also a term to describe the doctor who specializes in that type
of medicine.
The suffix for the study of that body system is “-logy”. There are a number of suffixes
for the physician who specializes in a particular body system. The most common is
“-logist”. Other suffixes that refer to a specialist of a particular body system are:
Û
Û
Û
Û
Û
Û
Table 2.4
-iatrist
-iatrics
-iatry
-ian
-ician
-ist
Medical Specialties and Specialists
Body System
Doctor Who Specializes
Medical Specialty
Digestive System
Gastroenterologist
Gastroenterology
Nervous System
Neurologist
Neurology
Reproductive System
(Female)
Gynecologist
Gynecology
Urinary System
Urologist
Nephrologist
Urology
Nephrology
Cardiovascular System
Cardiologist
Cardiology
Immune System
Immunologist
Immunology
Musculoskeletal system
Orthopedic Specialist
Orthopedics
Respiratory System
Respirologist
Respirology
Endocrine System
Endocrinologist
Endocrinology
Integumentary System
Dermatologist
Dermatology
Body Direction
Just as we have direction terms (north, south, east, west) to describe where we live, we
have direction terms to describe the various locations in the body. Because the body
can assume so many different positions (sitting, standing, lying down) it creates difficulty
in trying to describe location, so we consider the anatomical position when we are trying
to define direction.
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Table 2.5
Directional Terms
Term
Definition and Examples
Medical Term
Above or toward the head
Example: The head is superior to the neck
Below; toward the tail
Example: The neck is inferior to the head.
super/o
Toward the front surface of the body
Example: The abdominal cavity is anterior to the
spinal cavity
Toward the back surface of the body.
Example: The spinal cavity is posterior to the
thoracic cavity
anter/o
ventr/o
Medial
Toward the midline of the body (Midline is an
imaginary line drawn down through the center of the
body from the head to the feet)
Example: The big toe is medial to the small toe
medi/o
Lateral
Away from the midline
Example: The ear is lateral to the nose
later/o
Proximal
Toward the point of origin, or nearest the point of
attachment to the trunk.
Example: The elbow is proximal to the wrist and the
wrist is proximal to the fingers.
proxim/o
Distal
Farthest away from the point of origin or farthest
away from the point of attachment to the trunk.
Example: The intestines are distal to the stomach
and the stomach is distal to the esophagus.
dist/o
Peripheral
Away from the center
Example: Peripheral nerves are those that go away
from the brain and spinal cord.
Supine
Lying on the back and facing up
Prone
Lying on the abdomen, facing down.
Superior
Inferior
Anterior or Ventral
Posterior or Dorsal
infer/o
poster/o
dors/o
Body Organization
Just as a backpack is divided into different sections, the body consists of a number of
cavities. The two main body cavities are the:
Û
Û
Dorsal (door-sal): the back.
Ventral (ven-tral): the front.
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Each of these cavities is further divided into smaller cavities:
Û
Dorsal
Û
Ventral
%
%
%
%
%
Cranial (kray-nee-al)
Spinal (spy-nal)
Thoracic (thoh -ras-ick)
Abdominal (ab-dom-ih-nal)
Pelvic (pel-vick)
Summary Highlights for Chapter 2
The levels of organization within the body are: cells
> tissues > organs > systems > organism.
The major cavities of the body are the dorsal and
ventral. Each of these cavities is further
subdivided.
Summary Exercises: Chapter 2
Exercise 2.1 Fill in the blank with the correct answer.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
The cavity that contains the kidneys is the _________________________ cavity.
Sally Trotter’s dentist said the lesion was on the ______________________ of
her tongue. This means it was located on the upper surface of the tongue.
Mr. Holm’s had a fracture of the _______________________ forearm. This
means the fracture was located at the point of the forearm farthest away from the
shoulder joint.
Lying on the abdomen, face down, describes the __________________ position.
The ________________________________________ is proximal to the elbow.
A/An ________________________________ specializes in the diagnosis of
heart problems.
A/An _____________________________ is the basic structural unit of the body.
The study of the nervous system is called ______________________________.
If you were being treated by a skin specialist you would be seeing which type of
doctor__________________________________________________________.
___________________ and ____________________ are two types of
connective tissue.
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Exercise 2.2 Select the option provided that best answers the question.
1.
The term meaning toward the midline?
1.
Medial
2.
Distal
3.
Lateral
2.
The basic structural unit of the body is the:
1.
Heart
2.
Cell
3.
Tissue
4.
Gland
3.
Which term best describes the act of rotating the arm so the palm of the hand is
turned downward?
1.
Circumduction
2.
Supination
3.
Pronation
4.
Which directional term means situated below?
1.
Medial
2.
Inferior
3.
Distal
5.
Which term means away from the center?
1.
Peripheral
2.
Superficial
3.
Supine
6.
Which term refers to the back of the body or organ?
1.
Cephalic
2.
Ventral
3.
Dorsal
7.
Which term means lowermost, below, or toward the feet.
1.
Inferior
2.
Sagittal
3.
Superior
8.
A physician who specializes in the study of diseases of glands that secrete
directly into the blood is a/an:
1.
Immunologist
2.
Pathologist
3.
Endocrinologist
4.
Internist
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9.
The study of the structure, composition and function of tissue is referred to as:
1.
Cytology
2.
Histology
3.
Pathology
4.
Oncology
10.
The correct medical root for gland is:
1.
Adren/o
2.
Aden/o
3.
Anter/o
Exercise 2.3 Match the term in Column A with the correct definition in Column B.
Column A
Column B
1.
2.
Aplasia
Hyperplasia
3.
Anaplasia
4.
Hypoplasia
_____ Incomplete tissue development.
_____ A change in the structure of cells and in their
orientation to each other.
_____ An abnormal increase in the number of normal
cells.
_____ Lack of development of tissue.
Exercise 2.4
Label the parts of the cell on the diagram below
A: _________________________
B: _________________________
C: _________________________
A
B
C
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Challenge Exercise
Using the following word parts as your reference, complete the following
statements.
aden/o = gland
geront/o = old age
gynec/o = female
hist/o = tissue
nephr/o = kidney
neur/o = nerve
-oma = tumor, neoplasm
-logist = specialist
-logy = study of
-pathy = disease, suffering
1.
A/An __________________________________ is a tumor of kidney tissue.
2.
The study of the nervous system is called __________________________.
3.
_______________________ is the study of the process of aging.
4.
____________________ is a specialist in the study of cells.
5.
____________________ is the medical specialty concerned with diseases of
the female reproductive system.
6.
________________________ means disease of the glands and usually
involves swelling.
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