Chapter 1:
The
Human
Body
Anatomy and Physiology
• Anatomy – structure of body parts and their
relationships to one another
• Physiology – function of body, how body
works and carries out life sustaining activities
Anatomy and Physiology Topics
• Gross or Macroscopic Anatomy – large body structures,
ex. Heart, lungs, kidney
• Regional Anatomy – all structures in a particular region
• Systemic Anatomy – body structures, studied system by
system
• Surface Anatomy – internal structures as they relate to
overlying skin surface
• Microscopic Anatomy – structures that can not be seen
with the naked eye
– Cytology – cells of body
– Histology – study of tissues
• Developmental Anatomy – structural changes
– Embryology – development before birth
Topics of Physiology
• Operation of specific organs
– Ex. Renal physiology – kidney function and urine
production
– Neurophysiology – workings of NS
• Cellular molecular level
Levels of Organization
Chemical Level – simplest level, atoms combine to form molecules (proteins
& water)
Cellular Level – cells – simplest unit of living things
Tissue Level – groups of similar cells that have a common function
– 4 basic tissue types – epithelium, muscle, nervous, and connective
Organ level – structure composed of at least 2 tissue types – complex
functions
Organ System level – organs that work together to accomplish a common
purpose
Organismal level – organism sum total of all structural levels working
together
Different Systems of the 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.
Figure 1.3a
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.
Figure 1.3b
Skeletal
muscles
(c) Muscular System
Allows manipulation of the environment,
locomotion, and facial expression. Maintains posture, and produces heat.
Figure 1.3c
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.
Figure 1.3d
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.
Figure 1.3e
Heart
Blood
vessels
(f) Cardiovascular System
Blood vessels transport blood,
which carries oxygen, carbon
dioxide, nutrients, wastes, etc.
The heart pumps blood.
Figure 1.3f
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.
Figure 1.3g
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.
Figure 1.3h
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.
Figure 1.3i
Kidney
Ureter
Urinary
bladder
Urethra
(j) Urinary System
Eliminates nitrogenous wastes from the
body. Regulates water, electrolyte and
acid-base balance of the blood.
Figure 1.3j
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.
Figure 1.3k-l
Maintaining Life
1. Maintaining Boundaries –
- Internal environment separate from external
environment
- Cells surrounded by membrane
- Body surrounded by integument system
(skin)
- Protects from drying out, bacteria, damaging
affects of the heat, sunlight, and chemicals
Maintaining Life
2. Movement –
- Activities promoted by muscular system
- Skeletal system – framework that muscles pull
on
- Substances propelled through
body – urine, food, etc.
- Contractility – cells ability to
move by shortening
Maintaining Life
3. Responsiveness –
- Irritability
- Ability to sense changes (stimuli) in
environment
- Mainly – nervous system
Maintaining Life
4. Digestion –
- Breaking down of ingested food foodstuffs
- Nutrients delivered by blood
Maintaining Life
5. Metabolism –
- Chemical reactions
- Catabolism – breaking down substances into
simpler substances
- Anabolism – synthesizing complex substances
from simpler substances
Maintaining Life
6. Excretion - Process of removing
wastes
- Digestive system –
undigested food
- Respiratory system carbon dioxide
- Urinary system –
nitrogenous wastes
Maintaining Life
7. Reproduction –
- Cellular – cell division
- Organism –
egg + sperm  fertilized egg
Maintaining Life
8. Growth –
- Increase in size of body part or organism
- Increase in the number of cells
Survival Needs
1. Nutrients – carbohydrates, proteins, fat,
mineral/vitamins
2. Oxygen – oxidative reactions – require oxygen
3. Water – 60-90% of organism, watery environment
required for chemical reactions
4. Normal Body Temperature – 37 C (98.6 F)
-
Lower – reactions slow down and wills top
Higher – reactions speed up and proteins denature
5. Atmospheric Pressure – force air exerts on surface,
breathing and gas exchange depend on pressure
Homeostasis
•
•
•
•
Communication essential
Maintained by nervous and endocrine system
Variable – factor or event being regulated
Receptor – sensor that monitors the environment and
responds to changes – stimuli
– Sends info to control center – afferent pathway
• Control Center – determines set point and appropriate
response
– Output (efferent pathway) to effector
• Effector – means for response, reduces (negative
feedbacks) shuts off or enhances (positive feedback)
Negative Feedback Mechanism
• Prevents sudden change in body
• Regulates things like heart, BP, breathing rate,
blood gas levels, etc.
Positive Feedback Mechanism
•
•
•
•
•
Result or response enhances original stimulus
Response accelerated
Result in same direction as original response
Cascades
Ex. Oxytocin – labor – contractions stimulate
more contractions
Homeostatic Imbalance
• Most diverse – result from imbalance
• As age – control less efficient
• Increase risk of illness
Anatomical Language
•
•
•
•
Anatomical Position –
body erect w feet slightly apart
Standing at attention
Right and left – of person or cadaver NOT of
observer
Directional Terms
• Explain one body structure in relation to
another
• Superior (cranial) –
toward the head end (above)
• Anterior (caudal) –
away from head (below)
Directional Terms
• Ventral (anterior) – toward
front of body, in front of
• Dorsal (posterior) – toward
back of body, behind
Directional Terms
• Medial – toward midline,
inner side
• Lateral –
away from midline, outer side
• Intermediate – between a more
medial or more lateral structure
Directional Terms
• Proximal – closer to point of origin
of body part or point of attachment
to body trunk
• Distal – further from point of origin
or point of attachment
• Superficial (external) – toward or at
the surface of the body
• Deep (internal) – away from body
surface
Regional Terms
• Axial – main axis – head neck, trunk
• Appendicular – appendages or limbs
Planes
• Sagittal Plane – vertical
plane, divides the body into
right and left
• Median Plane – midsagittal
plane – sagittal plane
exactly at midline
• Parasagittal plane – set off
from midline
Planes
• Frontal Planes –
vertically divide
body into anterior
and posterior
• Also called coronal
plane
Planes
• Transverse (horizontal)
Plane – horizontally left
to right, divides into
superior and inferior
parts (cross section)
Planes
• Oblique Section – cuts made diagonally
between horizontal and vertical planes
Body Cavities
1. Dorsal Body
cavity – protects
NS organs
2 subdivisions –
-
Cranial cavity –
skull
Vertebral or
spinal cavity –
with in vertebrae
Body Cavities
2. Ventral Body
Cavity – thoracic
cavity and
abdominopelvic
cavity
- Houses internal
organs – viscera
Ventral Body Cavity
- Thoracic cavity – pleural cavities (2 – lungs)
- Medial mediastinum – contains pericardial cavity –
heart, esophagus, etc.
- Abdominopelvic cavity – 2 parts
- Abdominal cavity – stomach, intestines, spleen, liver,
etc.
- Pelvic cavity – bony pelvis, urinary bladder, some repo
organs, rectum
- Abdominal cavity – most susceptible to injury –
no bony covering, only muscle
Membranes
• Serosa or Serous Membrane – think double
layered
• Covers ventral body cavity
• Parietal Serosa – lines cavity walls
• Visceral Serosa – covers organs
• Serous fluids – lubricating fluid secreted by
membranes
Abdominopelvic Cavity
• Can also be divided
into quadrants
• RUQ – right upper
• LUQ – left upper
• RLQ – right lower
• LLQ – left lower
Abdominopelvic Cavity
• Can also be divided into regions
Other Body Cavities
1. Oral and digestive cavity – continuous
mouth to anus, oral – mouth – teeth and
tongue
2. Nasal Cavity – within and posterior to nose
3. Orbital Cavity – houses eyes
4. Middle Ear Cavities – medial to eardrums,
tiny bones that transmit sounds
5. Synovial Cavity – joint cavities