Download Orientation to the Human Body

Anatomy & Physiology I
Chapter 1
Anatomy: The study of form (structure)
Subdivisions:
Gross Anatomy - study of structures that can
be seen with the naked eye
Neuroanatomy – study of nervous system
structure
Microscopic Anatomy – study of structures that
are too small to see with the naked eye
Cytology – study of cells
Histology – study of tissues
Physiology: The study of function at
many levels
Subdivisions are based on organ systems
neurophysiology (physiology of nervous
system)
endocrinology (physiology of hormones)
pathophysiology (mechanisms of disease)
The Human Body
All living things are organized.
Atoms
Molecules
Organelles
Cells
Tissue
Organ
Organ System
Organism
Atoms
Molecule
1 Chemical level
Atoms combine to form molecules.
Atoms
Molecule
1 Chemical level
Atoms combine to form molecules.
Organelle
Smooth muscle cell
2 Cellular level
Cells are made up of
molecules.
Atoms
Molecule
1 Chemical level
Atoms combine to form molecules.
Organelle
Smooth muscle cell
2 Cellular level
Cells are made up of
molecules.
Smooth muscle tissue
3 Tissue level
Tissues consist of similar
types of cells.
Atoms
Molecule
1 Chemical level
Atoms combine to form molecules.
Organelle
Smooth muscle cell
2 Cellular level
Cells are made up of
molecules.
Smooth muscle tissue
3 Tissue level
Tissues consist of similar
types of cells.
Blood vessel (organ)
Smooth muscle tissue
Connective tissue
Epithelial
tissue
4 Organ level
Organs are made up of different types
of tissues.
Atoms
Organelle
Smooth muscle cell
Molecule
1 Chemical level
Atoms combine to form molecules.
Cardiovascular
system
Heart
Blood
vessels
2 Cellular level
Cells are made up of
molecules.
Smooth muscle tissue
3 Tissue level
Tissues consist of similar
types of cells.
Blood vessel (organ)
Smooth muscle tissue
Connective tissue
Epithelial
tissue
4 Organ level
Organs are made up of different types
of tissues.
5 Organ system level
Organ systems consist of different
organs that work together closely.
Atoms
Organelle
Smooth muscle cell
Molecule
1 Chemical level
Atoms combine to form molecules.
Cardiovascular
system
Heart
Blood
vessels
2 Cellular level
Cells are made up of
molecules.
Smooth muscle tissue
3 Tissue level
Tissues consist of similar
types of cells.
Blood vessel (organ)
Smooth muscle tissue
Connective tissue
Epithelial
tissue
4 Organ level
Organs are made up of different types
of tissues.
6 Organismal level
The human organism is made up
of many organ systems.
5 Organ system level
Organ systems consist of different
organs that work together closely.
Atoms – the smallest units (building blocks) of matter.
Molecules – make up organelles and other cellular
components
macromolecules – proteins, carbohydrates, fats,
DNA
Organelles – microscopic structures in a cell that carry
out its individual functions
Cells – smallest unit of life
Cells
The smallest units of an organism that carry
out all the basic functions of life
Perform all activities necessary to maintain
life
Metabolism, digestion, assimilation, excretion,
reproduction
Tissues
A mass of similar cells and cell products that form
discrete region of an organ and performs a specific
function
Four Tissue Classes
Epithelial: covers and protects
Connective: binds and supports other tissues
Muscle: movement
Nervous: connects sensory structures to motor
structures
Organs
Structure composed of two or more tissue types
that work together to carry out a particular
function
Cells integrated into tissues
Serve a common function
Examples
Brain
Heart
Lungs
Pancreas
An Organ System is a group of organs
Protection, support, and movement
Integumentary - Skeletal - Muscular
Coordination and control
Nervous - Endocrine
Circulation
Cardiovascular - Lymphatic
Nutrition and fluid balance
Respiratory - Digestive - Urinary
Production of offspring
Reproductive
The Human Body
Hair
Skin
Nails
(a) Integumentary System
Forms the external body covering, and
protects deeper tissues from injury.
Synthesizes vitamin D, and houses
cutaneous (pain, pressure, etc.)
receptors and sweat and oil glands.
Bones
Joint
(b) Skeletal System
Protects and supports body organs,
and provides a framework the muscles
use to cause movement. Blood cells
are formed within bones. Bones store
minerals.
Skeletal
muscles
(c) Muscular System
Allows manipulation of the environment,
locomotion, and facial expression. Maintains posture, and produces heat.
Brain
Spinal
cord
Nerves
(d) Nervous System
As the fast-acting control system of
the body, it responds to internal and
external changes by activating
appropriate muscles and glands.
Pineal gland
Pituitary
gland
Thyroid
gland
Thymus
Adrenal
gland
Pancreas
Testis
Ovary
(e) Endocrine System
Glands secrete hormones that regulate
processes such as growth, reproduction,
and nutrient use (metabolism) by body
cells.
Heart
Blood
vessels
(f) Cardiovascular System
Blood vessels transport blood,
which carries oxygen, carbon
dioxide, nutrients, wastes, etc.
The heart pumps blood.
Red bone
marrow
Thymus
Lymphatic
vessels
Thoracic
duct
Spleen
Lymph
nodes
(g) Lymphatic System/Immunity
Picks up fluid leaked from blood vessels
and returns it to blood. Disposes of debris
in the lymphatic stream. Houses white
blood cells (lymphocytes) involved in
immunity. The immune response mounts
the attack against foreign substances
within the body.
Nasal
cavity
Pharynx
Larynx
Trachea
Bronchus
Lung
(h) Respiratory System
Keeps blood constantly supplied with
oxygen and removes carbon dioxide.
The gaseous exchanges occur through
the walls of the air sacs of the lungs.
Oral cavity
Esophagus
Liver
Stomach
Small
intestine
Large
intestine
Rectum
Anus
(i) Digestive System
Breaks down food into absorbable
units that enter the blood for
distribution to body cells. Indigestible
foodstuffs are eliminated as feces.
Kidney
Ureter
Urinary
bladder
Urethra
(j) Urinary System
Eliminates nitrogenous wastes from the
body. Regulates water, electrolyte and
acid-base balance of the blood.
Mammary
glands (in
breasts)
Prostate
gland
Ovary
Penis
Testis
Scrotum
Ductus
deferens
Uterus
Vagina
Uterine
tube
(l) Female Reproductive System
(k) Male Reproductive System
Overall function is production of offspring. Testes produce sperm and male sex
hormone, and male ducts and glands aid in delivery of sperm to the female
reproductive tract. Ovaries produce eggs and female sex hormones. The remaining
female structures serve as sites for fertilization and development of the fetus.
Mammary glands of female breasts produce milk to nourish the newborn.
All cells depend on organ systems to meet their
survival needs
Organ systems work cooperatively to perform
necessary life functions
Digestive system
Takes in nutrients, breaks them down,
and eliminates unabsorbed matter
(feces)
Food
Respiratory system
Takes in oxygen and
eliminates carbon dioxide
O2
CO2
Cardiovascular system
Via the blood, distributes oxygen
and nutrients to all body cells and
delivers wastes and carbon
dioxide to disposal organs
Blood
CO2
O2
Heart
Nutrients
Interstitial fluid
Urinary
system
Eliminates
nitrogenous
wastes and
excess ions
Nutrients and wastes pass
between blood and cells
via the interstitial fluid
Feces
Integumentary system
Protects the body as a whole
from the external environment
Urine
Metabolism and Its Regulation
All the life-sustaining chemical reactions that
occur within body cells
Types of metabolism
Anabolism – reactions that build (synthesize) larger,
more complex structures from simpler substances.
Similar to building a pearl necklace from individual pearls.
In cells, anabolic reactions require ATP for energy.
Catabolism – reactions that breakdown larger, more
complex substances to simpler substance.
Similar to removing each individual pearl from a pearl
necklace
Catabolic reactions, like glycolysis, release energy. This
energy can be used in cells to make ATP.
stable internal conditions regardless of external
conditions
fluctuates within limited range around a set point
Homeostatic Control Mechanisms – Mechanisms that
help to maintain homeostasis
The body has hundreds of homeostatic mechanisms,
including mechanisms to control:
Body temperature, blood sugar, blood pH, water balance,
blood pressure, electrolyte balance, etc.
When these mechanisms don’t work normally, the result
can be disease, dysfunction or death.
Involve continuous monitoring and regulation of
many factors (variables)
Nervous and endocrine systems accomplish the
communication via nerve impulses and
hormones
Usually involves negative feedback loop
Negative feedback loops have 3 components
Receptor
Control Center
Effector
Body senses a change and activates mechanisms
to reverse it
The response reduces or shuts off the original
stimulus
Examples:
Regulation of body temperature and blood pressure
(two nervous system mechanism)
Regulation of blood volume by ADH (an endocrine
mechanism)
1. Receptor (sensor)
Monitors the environment and responds to stimuli
(changes in controlled variables)
Reports changes to the control center
2. Control center
Determines the set point at which the variable is
maintained
Receives input from receptor when variable is out
of range
Determines appropriate response; delivers
instructions to the appropriate effector
3. Effector
Receives signal (command) from control center
Provides the means to respond
Response acts to reduce or enhance the stimulus
(feedback)
1
Stimulus
produces
change in
variable.
BALANCE
2
Receptor
detects
change.
Receptor
1
Stimulus
produces
change in
variable.
BALANCE
3 Input: Information
sent along afferent
pathway to control
center.
2
Receptor
detects
change.
Receptor
Control
Center
Afferent
pathway
1
Stimulus
produces
change in
variable.
BALANCE
3 Input: Information
sent along afferent
pathway to control
center.
2
Receptor
detects
change.
Receptor
4 Output:
Control
Center
Afferent
Efferent
pathway
pathway
1
Stimulus
produces
change in
variable.
BALANCE
Information sent along
efferent pathway to
effector.
Effector
3 Input: Information
sent along afferent
pathway to control
center.
2
Receptor
detects
change.
Receptor
4 Output:
Control
Center
Afferent
Efferent
pathway
pathway
1
Stimulus
produces
change in
variable.
BALANCE
Information sent along
efferent pathway to
effector.
Effector
5
Response
of effector
feeds back
to reduce
the effect of
stimulus
and returns
variable to
homeostatic
level.
Control Center
(thermoregulatory
center in brain)
Information sent
along the afferent
pathway to control
center
Afferent
pathway
Information sent
along the efferent
pathway to
effectors
Efferent
pathway
Receptors
Temperature-sensitive
cells in skin and brain
Effectors
Sweat glands
Sweat glands activated
Response
Evaporation of sweat
Body temperature falls;
stimulus ends
Stimulus
Body temperature
rises
BALANCE
Stimulus
Response
Body temperature rises;
stimulus ends
Body temperature falls
Receptors
Temperature-sensitive
cells in skin and brain
Effectors
Skeletal muscles
Shivering
begins
Efferent
pathway
Information sent
along the efferent
pathway to effectors
Afferent
pathway
Control Center
(thermoregulatory
center in brain)
Information sent
along the afferent
pathway to control
center
Sitting up in bed causes a drop in blood pressure in the
head and upper thorax
Receptors in the arteries near the heart alert the
control center in the brainstem
Control center in the brain sends nerve signals to the
heart (effector)
The effector (the heart) receives a command signal to
increases the heart rate. This returns the blood
pressure to normal
Failure of this to feedback loop may produce dizziness
in the elderly
Person rises
from bed
Blood pressure rises
to normal; homeostasis
is restored
Blood drains from
upper body, creating
homeostatic imbalance
Cardiac center
accelerates heartbeat
Baroreceptors above
heart respond to drop
in blood pressure
Baroreceptors send signals
to cardiac center of brainstem
Receptors sense decreased blood volume (as
occurs with dehydration)
Control center in hypothalamus stimulates
pituitary gland to release antidiuretic hormone
(ADH)
ADH causes the kidneys (effectors) to return
more water to the blood
The response enhances or exaggerates the
original stimulus
May exhibit a cascade or amplifying effect
Usually controls infrequent events e.g.:
Enhancement of labor contractions by oxytocin
Platelet plug formation and blood clotting
Self-amplifying cycle
leads to greater change in the same direction
feedback loop is repeated – change produces more change
Normal way of producing rapid changes
occurs with childbirth, blood clotting, protein digestion, fever, and
generation of nerve signals
3 Brain stimulates
pituitary gland to
secrete oxytocin
2 Nerve impulses
from cervix
Transmitted
to brain
4
Oxytocin stimulates uterine
contractions and pushes
fetus toward cervix
1 Head of fetus
pushes against cervix
1 Break or tear
occurs in blood
vessel wall.
Positive feedback
cycle is initiated.
1 Break or tear
occurs in blood
vessel wall.
Positive feedback
cycle is initiated.
2 Platelets
adhere to site
and release
chemicals.
1 Break or tear
occurs in blood
vessel wall.
Positive feedback
cycle is initiated.
3 Released
chemicals
attract more
platelets.
2 Platelets
Positive
feedback
loop
adhere to site
and release
chemicals.
1 Break or tear
occurs in blood
vessel wall.
Positive feedback
cycle is initiated.
3 Released
chemicals
attract more
platelets.
2 Platelets
Positive
feedback
loop
adhere to site
and release
chemicals
(clotting factors).
Feedback cycle ends
when plug is formed.
4 Platelet plug
forms.
Fever > 104 degrees F
metabolic rate increases
body produces heat even faster
body temperature continues to rise
further increasing metabolic rate
Cycle continues to reinforce itself
Becomes fatal at 113 degrees F
Disturbance of homeostasis
Increases risk of disease
Contributes to changes associated with
aging
May allow destructive positive feedback
mechanisms to take over (e.g., heart failure)
Anatomical Position - Standard frame of reference for
anatomical descriptions & dissection
Anatomical Divisions – The two fundamental divisions of
the human body (axial & appendicular)
Body Regions – Regional terms designate specific areas
Directions - Consistent terms are used to designate position
and direction to avoid inaccuracy.
Planes - implies an imaginary flat surface passing through the
body
Cavities - Internally, the body is divided into spaces, or cavities,
that contain organs.
Standard anatomical body position:
Person stands erect
face & eyes facing forward
Feet flat on floor, slightly apart
Arms at sides
Palms face forward (forearms in
supine position)
When supinated
palms face forward or upward
radius & ulna are parallel
When pronated
palms face rearward or downward
radius & ulna are crossed
supine
prone
Axial region = head, neck & trunk
thoracic region = trunk above diaphragm
abdominal region = trunk below diaphragm
divided into 4 quadrants / 9 regions by tic-tac-toe grid
Appendicular region = upper & lower limbs
upper limb - arm (brachial region), forearm (antebrachial
region), wrist (carpal region), hand (manual region), fingers
(digits)
lower limb - thigh (femoral region), leg (crural region),
ankle (tarsal region), foot (pedal region), toes (digits)
Cephalic
Frontal
Orbital
Nasal
Oral
Mental
Cervical
Thoracic
Axillary
Mammary
Sternal
Abdominal
Umbilical
Pelvic
Inguinal
(groin)
Pubic
(genital)
Thorax
Abdomen
Back (Dorsum)
Upper limb
Acromial
Brachial (arm)
Antecubital
Antebrachial (forearm)
Carpal (wrist)
Manus (hand)
Palmar
Pollex
Digital
Lower limb
Coxal (hip)
Femoral (thigh)
Patellar
Crural (leg)
Fibular or peroneal
Pedal (foot)
Tarsal (ankle)
Metatarsal
Digital
Hallux
Upper limb
Acromial
Brachial (arm)
Olecranal
Antebrachial
(forearm)
Manus (hand)
Cephalic
Otic
Occipital (back of head)
Cervical
Nuchal (back of neck)
Back (dorsal)
Scapular
Metacarpal
Vertebral
Digital
Lumbar
Sacral
Lower limb
Femoral (thigh)
Gluteal
Popliteal
Perineal (between anus and
external genitalia)
Sural (calf)
Fibular or peroneal
Pedal (foot)
Calcaneal
Plantar
Thorax
Abdomen
Back (Dorsum)
Plane: Flat surface along which body or
structure is cut for anatomical study
Sagittal plane
Divides body vertically into right and left parts
Produces a sagittal section
Midsagittal (median) plane
Lies on midline
Parasagittal plane
Not on midline
Plane implies an imaginary flat surface passing
through the body
Sagittal plane divides body into right and left regions
midsagittal (median) plane divides body or organ into equal
halves
parasagittal plane divides body into unequal parts
Frontal (coronal) plane divides body into anterior &
posterior portions
Transverse (horizontal) plane divides the body into
superior & inferior portions
Section implies actual cut or slice to reveal internal
anatomy
Frontal plane
Median (midsagittal) plane
Transverse plane
(a) Frontal section
(through torso)
(b) Transverse section
(through torso,
inferior view)
Pancreas
(c) Median section
(midsagittal)
Aorta
Spleen
Left and
Liver Heart Spleen
right lungs
Stomach
Arm
Liver
Spinal cord
Body wall
Subcutaneous fat layer
Intestines
Rectum
Vertebral
column
Dorsal cavity
Protects nervous system
Two subdivisions:
Cranial cavity
Encases brain
Vertebral cavity
Encases spinal cord
Ventral cavity
Houses internal organs (viscera)
Two subdivisions (separated by diaphragm):
Thoracic cavity
Abdominopelvic cavity
Cranial
cavity
Cranial
cavity
(contains
brain)
Dorsal
body
cavity
Dorsal body cavity
Ventral body cavity
Vertebral
cavity
Superior
mediastinum
Pleural
cavity
Pericardial
cavity within
the mediastinum
Diaphragm
Thoracic
cavity
(contains
heart and
lungs)
Vertebral
cavity
(contains
spinal
cord)
(a) Lateral view
Ventral body
cavity
(thoracic and
Abdomino- abdominopelvic
pelvic
cavities)
cavity
Abdominal cavity
(contains digestive
viscera)
Pelvic cavity
(contains urinary
bladder, reproductive
organs, and rectum)
(b) Anterior view
Thoracic cavity subdivisions:
Two pleural cavities
Each houses a lung
Mediastinum
Contains pericardial cavity
Surrounds thoracic organs
Pericardial cavity
Encloses heart
Abdominopelvic cavity subdivisions:
Abdominal cavity
Contains stomach, intestines, spleen, and liver
Pelvic cavity
Contains urinary bladder, reproductive organs, and
rectum
Cranial
cavity
Cranial
cavity
(contains
brain)
Dorsal
body
cavity
Dorsal body cavity
Ventral body cavity
Vertebral
cavity
Superior
mediastinum
Pleural
cavity
Pericardial
cavity within
the mediastinum
Diaphragm
Thoracic
cavity
(contains
heart and
lungs)
Vertebral
cavity
(contains
spinal
cord)
(a) Lateral view
Ventral body
cavity
(thoracic and
Abdomino- abdominopelvic
pelvic
cavities)
cavity
Abdominal cavity
(contains digestive
viscera)
Pelvic cavity
(contains urinary
bladder, reproductive
organs, and rectum)
(b) Anterior view
Thin, double-layered membrane separated by
serous fluid
Parietal serosa lines internal body walls
Visceral serosa covers the internal organs
Outer balloon wall
(comparable to parietal serosa)
Air (comparable to serous cavity)
Inner balloon wall
(comparable to visceral serosa)
Heart
Parietal
pericardium
Pericardial
space with
serous fluid
Visceral
pericardium
(b) The serosae associated with the heart.
Abdominopelvic Quadrants
Divisions used primarily by
medical personnel
Right upper
quadrant
(RUQ)
Left upper
quadrant
(LUQ)
Right lower
quadrant
(RLQ)
Left lower
quadrant
(LLQ)
Abdominopelvic Regions
Nine divisions used primarily by anatomists
Right
Epigastric
hypochondriac
region
region
Right
lumbar
region
Umbilical
region
Right iliac Hypogastric
(inguinal) (pubic)
region
region
Left
hypochondriac
region
Left
lumbar
region
Left iliac
(inguinal)
region
(a) Nine regions delineated by four planes
Liver
Diaphragm
Gallbladder
Stomach
Ascending colon of
large intestine
Transverse colon
of large intestine
Small intestine
Descending colon
of large intestine
Cecum
Appendix
Initial part of
sigmoid colon
Urinary bladder
(b) Anterior view of the nine regions showing the superficial organs