Chapter 1
Introduction a nd Org anization
1.
Anatomy and physiology is the relationship of the structure and function of the human
body.
a.
Architect Louis Henry Sullivan coined the phrase Form follows func tion.
This is true of the human body. The function of a specific organ often dictates
what form it will take.
b.
Anatomy - the study of form
i.
Anatomy is derived for a Greek word meaning to cut apart (ana - up;
tome - to cut) which from the time of ancient Greece has been the method
for the study of ana tomy.
(1)
Most of the terms that form the language of anatomy are of Greek or
Latin origin.
(a)
List of common prefixes and suffixes inside from cover.)
ii.
c.
Study of Anato my can be d ivided into many parts
(1)
Surface anatomy - Study of the form and markings of the surface of
the body.
(2)
Gross (macroscopic anatomy) - study of large structures...that can
be examined without using a microscope.
(3)
Two methods of study..
(a)
Systemic (systematic)Anatomy(b)
Regional anatomy (4)
Histology - study of tissues (microscop ic anatomy)
(5)
Cytology - study of individual cells (either chemically or
micro sco pica lly - ele ctro n microsc opic level)
(6)
Anatom ic imag ing -using X-ray, ultrasound, MRI, etc.
Definition of Physiology
i.
Study of the function of the body.
ii.
Ma jor goals of physiology are:
(1)
To understa nd and predict the respo nses of the body to stimuli.
(2)
Understand how the body maintains conditions within a narrow
range of values in the p resence of a continually changing
environment.
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iii.
2.
Physiology like Anatomy can be broken dow n into multiple le vels or
disciplines depending on the structures and systems involved.
(1)
neurophysiology - function o f nerve ce lls
(2)
Endocrinology - hormones and how they control body function
(3)
Cardiova scular physiology
(4)
Immunology
(5)
Resp iratory physiology etc.
(6)
Cell physiology - function of individual cells
Structural and Functional Organization of the Body
a.
The body consists of several levels of structural organization. These structural
levels include: chemical, orga nelle, cell, tissue, o rgan, organ s ystem, orga nism.
i.
Chemical organization - ultimately everything that we are can be broken
down into specific chemicals.
(1)
(2)
(3)
ii.
Organelles - are small subs tructures that w hen collected together co nstitute
a ce ll. In c hapter 3 of this text we will discuss o rganelles in greater detail.
iii.
Cells - Cells are the smallest functional unit of life. All living things,
whether plant or animal are composed of cells.
(1)
(2)
iv.
Tissues - Tissues are composed of similar types of cells all put together.
(1)
In addition to cells, tissues are composed of extracellular substances
(or s ubstanc es fo und o utsid e of the cell) w hich help to bind the cells
together.
(2)
There are 4 primary types of tissues in the bo dy:
(a)
Epithelium,
(b)
Connective,
(c)
muscular and
(d)
nervous tissue
v.
Organs - Organs a re structures that are mad e up of two or more different
types of tissues.
(1)
Organs o ccur throughout the body and vary in size and function.
(2)
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b.
(3)
vi.
Organ system - also known as systems - These systems are composed of
multiple organs working together to perform a common function.
(1)
For example. The digestive syste m is composed of teeth, salivary
glands, mouth, esophagus, stomach, small and large intestines as
well as liver, pa ncreas, gallbladder etc . There a re many different
organ syste ms in the body.
vii. Organism - this obviously refers to the combination of all the organ
systems w hich form the overall organism.
Organ systems -we will use the systemic method of study rather than a regional
approa ch
i.
Integumentary system (1)
Form: skin, hair, nails and sweat glands
(2)
Fxn: external suppo rt and prote ction of the bod y.
ii.
Skeletal system (1)
Form: bones, assoc iated cartilage a nd joints
(2)
Fxn: internal support and flexible framework for body move ment;
production of blood cells.
iii.
Muscular sys tem (1)
Form: muscles attached to skeletal system
(2)
Fnx: body moveme nt and pos ture -- produc tion of body hea t.
iv.
Lymphatic system (1)
Form: lymph vessels, nodes and o ther lymph organs (spleen).
(2)
Fxn: body immunity, absorption of fats; drainage of tissue fluid.
v.
Endocrine System
(1)
Form: glands that secrete hormones ie. Pituitary, thyroid, adrenels,
ovaries/testes.
(2)
secretion o f hormones for che mical regulation.
vi.
Respiratory system
(1)
Form: lungs, bronchus , larynx, nasal ca vity, oral cavity
(2)
Fxn: gaseous exchange between external environment and blood.
vii. Nervous system
(1)
Form: brain, spinal cord, nerves, sens ory receptors
(2)
Fxn: control and regulation of other systems of body; detect
sensation intellectua l function.
viii. Circulatory system
(1)
Structure: Heart blood vessels and blood.
-3-
(2)
ix.
x.
xi.
3.
Fxn: transport of life sustaining materials to body cells; removal of
meta bolic wastes from cells
Digestive system
(1)
mouth, esophagus, stomach, intestines, and accessory organs ie.
liver, gall bladder.
(2)
Fxn: breakdo wn a nd abso rptio n of food materials
Urinary System
(1)
Form: kidney ureter urinary bladder urethra
(2)
Fxn: remove waste products form blood, regulate water balance, pH
and ion balance.
Reproductive System
(1)
Female: Form: ovary, ute rus vagina
(a)
production of female sex cells (ova)
(b)
site of fertilization, implantation of ovum and development of
embryo and fetus.
(c)
Produces milk for newb orn
(d)
produce s hormones that influence sexual function and
behavior. (P art of endoc rine function)
(2)
Male: Form: testes, prostate, ducts and penis.
(a)
production of male sex cells (sperm).
(b)
transfer of spe rm to female repro ductive syste m.
(c)
produce s hormones that influence sexual function and
behavior.
Useful T erminology a nd Concepts
a.
Homeostasis - this refers to a range of operating environments that are optimal for
life processes to o ccur.
i.
Homes tasis - Proc ess wher eby an orga nism ma intains a steady state
condition where cellular processes can be optimally performed.
(1)
Eg. body tempe rature
(a)
(2)
Ma intenance of c onstant internal environment in the face of widely
fluctuating external environment. (Discusse d in detail later).
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b.
Dire ctional Terms - Sinc e the scie nce of anatomy is a des criptive s cience, it is
important to have a basis o r a standa rd from which to b egin describing.
i.
Anatom ical Pos ition
(1)
Person standing erect, feet forward, arms hanging to side palms of
the hands facing forward with thumbs to outside.
ii.
Directional Terms (Table 1.1)
(1)
Right -right side of body- Eg. Right ear
(2)
Left -left side of body
(3)
Superior - higher or above
(a)
(4)
Inferior - lower or below
(a)
(5)
Anterior - before or in front of
(a)
(6)
Posterior - following or after
(a)
(7)
Cephalic - (rosteral) head - toward the head (closer to the head )
(a)
(8)
Caudal- tail closer to the tail (often synonymous with inferior)
(a)
(9)
Ventral - belly toward the b elly (syn with anterior)
(a)
(10) Dorsal - back toward the b ack (syn with pos terior)
(a)
(11) Proximal - nearest closer to the point of attachment to the body
(a)
(12) Distal - to sta nd apart distant farther from the point of atta chment to
the body.
(a)
(13) Med ial- middle toward the midline of the body
(a)
(14) Lateral - side away from the midline of the body
(a)
(15) Superficial - toward the surface
(a)
(16) Deep - away from the surface / internal
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(a)
(17) Prone - to lie or be placed with the anterior surface down
(18) Supine - to lie or be placed w ith the anterior surface up
c.
Planes
i.
Sagittal - runs vertic ally through the body and divide s it into right and left
portions.
(1)
Midsagittal- directly through the midline
(2)
Parasagittal- to one side of the midline
ii.
Transverse - Horizontal - parallel to the ground and divides into supeior /
inferior portions.
iii.
Frontal - Co ronal - runs vertic ally from right to left
iv.
Longitudina l section - cut through the long axis of an organ
v.
Cross section - right angle to the long axis
vi.
Oblique - cut across the lo ng axis at an angle o ther than a right angel.
d.
Body Re gions i.
Majo r body regions include: the head, neck, trunk , upper e xtremity and
lower extre mity
ii.
Head and Neck
(1)
Head - cephalic region
(2)
Facial region - eyes (orbita l), no se (nasal) and mo uth (o ral)
(3)
Cra nial - c overs the brain
(4)
Neck - Cervical region
iii.
Trunk (1)
thoracic region (thorax) - chest
(a)
Mamma ry region (surrounds the nipple on the b reast)
(b)
Sternal region (be tween ma mmary)
(c)
Axillary - arm pit region
(d)
Scapular region - shoulder blades
(e)
Vertebral region - extends length of back
(f)
Pectoral region - lateral side of thorax
(2)
Abd omina l regio n -be low thorax to pelvis
(a)
Quadra nts
(i)
Two imaginary line: one horizontal and one vertical
1)
intersect the navel Rt. & lt upper and lower
(b)
Nine regions by 4 imaginary lines (tic tac toe fig.)
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rt. Hypochondriac
epigastric
lt hypogastric
rt lumbar
umbilical
lt lumbar
rt iliac
hypo gastric
lt iliac
(3)
iv.
v.
e.
Pelvic region - lower portio n of the trunk asso ciated w ith the hip
(a)
pubic area - covered by pubic hair in mature individ uals
(b)
perineum - area of external sex o rgans and a nal opening
located
(c)
lumbar region - small of the back
(d)
sacral region - vertebral termination
(e)
gluteal region - large hip muscles.
Upper Extremities
(1)
Shoulder -acromial region
(2)
Brachium - upper arm (shoulder to elbow)
(3)
Antebrac hium - forearm (elbow to wrist)
(a)
Cubital region - elbow.
(4)
Manus - hand
(a)
Palmar re gion - palm
(b)
Dorsum - b ack of hand
Lower Extremities
(1)
Thigh - hip to knee (up per leg or femora l region)
(2)
Knee (a)
patellar region
(b)
popliteal region
(3)
Leg - knee to ankle
(4)
Pes - foot
(a)
plantar s urfac e - sole
(b)
dorsum - top surface
Body Ca vities and structures - confined spaces within the body that contain organs.
i.
Dorsa l (Posterior)C avity
(1)
Cranial
(a)
Brain
(2)
Spinal
(a)
Spine
ii.
Ventral (Anterior) Cavities (Cavities of the trunk)
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(1)
Can be divided into the Tho racic and the abdominop elvic cavity.
(a)
Thoracic C avity- surrounded by the rib cage and separated
from the abdo minal cavity by the muscular d iaphragm.
(i)
Pleural Cavities
1)
Contains: Lungs
(ii)
Me diastinum divides the ca vity into right and left.
1)
Contains: Great vessels, esophagus, trachea,
nerves
(iii) Perica rdial Ca vity - within the mediastinum.
1)
Contains: Heart
(b)
f.
Abdom inopelvic Ca vity - bounded by abdominal muscles
(two parts).
(i)
Abdominal (Peritoneal) Cavity 1)
Contains:
a)
Stomach
b)
Small Intestine
c)
Large Intestine
d)
Liver
e)
Rectum
(ii)
Pelvic 1)
small spa ce e nclosed by pelvis
2)
Not physically separated from the peritoneal
cavity
3)
contains:
a)
Bladder
b)
Repro ductive organs
Body Membranes (Serous Membranes)
i.
Cover, separa te and sup port the orga ns of the trunk ca vity and line the
trunk cavities.
(1)
Two types:
(a)
Mucous membranes - sec rete thick mucus (i)
line cavities that enter or exit the body (nose)
(b)
Serous membranes
(i)
line the thoracic and abdominal cavities
(ii)
secrete water lubricant (serous fluid)
(2)
Two general locations:
(a)
Viser al serous mem brane - in contact w ith the organ.
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(b)
g.
Parie tal serous mem brane - in co ntac t with (lines) the wall
of the cavity
(3)
Space betwe en membrane filled with a thin lubricating film.
(a)
Reduc es friction betw een organs
ii.
Cavities and their memb rane s:
(1)
Pleural ca vity- surrounds the lung.
(a)
pleurae (sg. Pleura) - sero us membrane s asso ciated w ith the
lungs
(b)
cavity contains pleural fluid.
(c)
parietal pleura -lines thoracic ca vity
(d)
viseral pleura - attached to the outer s urface of lungs
(2)
Perica rdial cavity - surrounds the he art a nd conta ins a small
amount of fluid.
(a)
viseral pericardium- outer layer of tissue attached to he art
(b)
parietal pericardium - surrounds the heart
(3)
Peritoneal c avity (a)
parieta l peritoneum - attaches to ab dominal w all
(b)
viscer al peritone um - attaches to viscera
(c)
mesentery - fused double layer of parietal peritoneum that
connects that parietal pe ritoneum to the visce ral peritoneum.
(i)
Functions
1)
anchors visc eral peritoneum (o rgans) to
abd omina l wall.
2)
provides a passa geway for b lood vess els and
nerves to enter organs.
(4)
Retroperitoneal
(a)
behind the pe ritoneum
(b)
Organs include the kidneys, adrenal glands , pancre as and
urinary bladder.
Homeos tasis
i.
Homeos tasis is the existe nce and ma intenance of a re latively constant
environment within the bo dy.
(1)
Normal functio n of each cell d epe nds on ma intenance of its fluid
environment within a co nstant.
(a)
temperature
(b)
volume.
(c)
chemical conte nt.
(2)
There is an ideal normal value for each of these called the set point.
(a)
The bod y does no t maintain these at a n exact pre cise set p oint
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(b)
ii.
iii.
but increase s and de crease s around the set point.
Organ syste ms he lp co ntrol the internal environment so it
remains relatively cons tant.
Negative feedback.
(1)
Most systems of the body are regulated by negative feedback.
(a)
brings variable ba ck to se t point
(2)
Three components:
(a)
Rece ptor (sens or)- monitors the d eviations from set p oint.
(i)
tension on a tendon, blood glucose, temp.
(b)
control (integrating )cente r - establishes a set po int
(i)
generally a portion of brain or spinal cord
(ii)
increases or decreases activity at an effector
(c)
effector - can change the value of the variable.
(i)
generally muscle or glands.
(3)
Receptor detects the stimulus and informs the control center which
analyzes the input from the receptor and send output to the effector
and the effector produces a response.
(4)
Example of blood pres sure
(a)
sensor in ca rotid sinus
(b)
integrating center in pons
(c)
heart is effector
(5)
Example of temp (Antagonistic effectors - shivering and sw eating)
(a)
sensor - hyp othamamus
(b)
intergrated in brain
(c)
effectors sweat glands / muscle.
Positive Feedback
(1)
Pos itive fe edb ack responses are not homeostatic and are rare in
healthy individuals.
(2)
Positive implies that a d eviation from normal value oc curs and the
response o f the system is to make the de viation greater.
(3)
Eg. Blood clotting - activation of one factor causes and avalanche effect -single change can
(4)
cause a blood clot.
Birth of baby...stretch of the uterine cervix causes uterus to contract which causes baby to
push against cervix even more which results in the increase contraction of the cervix etc....
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