Chapter 1
The Human Body: An
Orientation
Anatomy vs. Physiology

Anatomy- studies the structure of the body parts and
their relationships to one another (seen, felt, examined)
• Physiology- concerns the function of the body’s
structural machinery (how parts work and carry out
life sustaining activities)

Gross Anatomy- study of large body structures visible to
the naked eye
• Regional- One region studied in detail
• Systemic- Study system by system
• Surface- How organs relate to the skin
 Microscopic
Anatomy- parts of the body too small
to see with the naked eye (EX: thin slices of tissue)
• Cytology- study of cells
• Histology- study of tissue
Developmental anatomy- changes that occur throughout life
Embryology- changes that occur before birth (look at birth
defects)
Tools to Study anatomy

Observation
• Manipulation
• Palpation
(feeling organ with hands)
• Auscultation(listening to the organ sounds)
Working Together
*
What a structure can do depends
on its specific form – Principle of
Complementarity of Structure and
Function
Levels of Structural
Organization
Chemical (atoms form
molecules)
Organ Systems (organs working
together with common purpose)
Organ
Cells (smallest unit of
living things)
Tissue (group of cells with
common function)
Organ Systems
 1.
Cardiovascular
 2. Integumentary
 3. Skeletal
 4. Muscular
 5. Nervous
 6. Endocrine
Organ Systems (Cont.)
 7.
Respiratory
 8. Digestive
 9. Lymphatic
 10. Urinary
 11. Reproductive
Maintaining Life
 No
organ system works in isolation
they work cooperatively to promote
well-being of entire body.
1. Boundaries
 Single
Celled Organisms- outer
membrane to hold in all contents and
restrict foreign objects from entering
 **
All Cells of our body are surrounded by
a selectively permeable membrane
Boundaries (Cont)
 Whole
body protected by Integumentary
System or Skin

Protection From:





?
Drying out
Bacteria
Heat
Sun
Chemicals in the Environment
2. Movement
 Muscular
System allows for the
movements we make while the skeletal
system provides the framework for
muscles to pull on and create work
• Also have movement of items through
internal organs such as food, blood, urine
by contracting or shortening of muscle cells
3. Responsiveness
 Nervous
System – sends electric pulses to
stimuli from the environment
4. Digestion
 Break
food into simple molecules that can
be absorbed by blood
 Transported
through the body cells by the
cardiovascular system
5. Metabolism
 All
Chemical Reactions that occur within
the body cells
Systems Working Together: Metabolism
depends on Digestive & Respiratory Systems to
make nutrients and oxygen available to the
blood and Cardiovascular to distribute through
the body- regulated largely by hormones
secreted by the Endocrine System
6. Excretion
 Removing
Waste from the body
o Digestive System- rids indigestible
food
o Urinary- rids of nitrogen containing
waste- urine
o Respiratory- rid of Carbon Dioxide
7. Reproduction
 Can
be cellular or organismal level
• Cellular- original cell divides into daughter cells
• Organismal- sperm unites with egg to form an embryo
• Reproductive responsible for offspring
but function regulated by Hormones of Endocrine System
8. Growth
 Increase
in size of body part or organism

Can have increase in the number of cells or
increase in the individual cell size

Constructive activities must occur faster
than destructive activities to have growth
SURVIVAL NEEDS
 Body
Systems goal is to maintain life but
there are other factors that must be
present to do so
Including:
Nutrients
Oxygen
Water
Appropriate Temperature
Atmospheric Pressure
1. Nutrients
 Energy/
Cell Building
 Carbohydrates- major fuel for cells
 Proteins- essential for building cell
structures
 Fats- cushion body organs, insulate, and
provide energy- rich fuel reserve
 Select Minerals and Vitamins- chemical
reactions that go on in cells for oxygen
transport
2. Oxygen
 Human
cells can only survive a few
minutes without oxygen
 Approximately
oxygen
20 % of air we breathe is
3. Water
 60
to 80 % of body weight
 Single most abundant chemical
substance in the body
• Provides a base for chemical reactions and body
secretions and excretions
• Obtain mostly from foods we eat
• Lost by evaporation from lungs, skin, and body
excretions
4. Normal Body Temperature

Muscular System produces most body heat

As temperature drops below 98 F metabolic
reactions become slower until they eventually stop
 If
temperature is too high chemical
reactions occur at a frantic pace and
cause proteins to lose their shape and
stop functioning
5. Atmospheric Pressure
 Force
air exerts on surface of the body
 Breathing and gas exchange in the lungs
depends on appropriate atmospheric
pressure
 High
altitudes cause atmospheric pressure
to be lower and the air to be thin- gas
exchange may be inadequate for cellular
metabolism
BALANCE IS IMPORTANT
 It
is very important to have each of the
needs in the appropriate amount


Too much oxygen- toxic to body
Too much/ little food- obesity/ starvation
Homeostasis
 The
body’s ability to maintain relatively
stable internal conditions even though the
outside world changes continuously
*
Communication Is KEY- Nervous and
Endocrine systems very important for this
state of balance
Negative Feedback



System shuts off original stimulus or reduces it
Change in direction
Controls the everyday (moment to moment
changes in Homeostasis of body)
“
Like your Thermostat at Home”
 Your
thermostat is known as the
hypothalamus located in your brain
Positive Feedback
 Enhances
original stimulus
 Proceeds
in the same direction
 Usually
control infrequent events such as
blood clotting, or enhancing labor
contractions during child birth
Homeostatic Imbalance
 Diseases
 As
we age body is less efficient at fighting
illness
 Could
also come from negative
feedback mechanisms being
overwhelmed and destructive positive
feedback mechanisms taking over
Example= HEART FAILURE
Language of Anatomy
 Anatomical
Position- standing straight,
feet slightly apart, palms facing forwards

“standing at attention”
 “right”
and “left” on the person not from
observers viewpoint
Regional Terms
 Axial-
main axis (head, neck, trunk)
 Appendicular-
appendages or limbs
Body Planes
 Sagittal-
right
 Frontal-
Vertical/ divided into left and
Vertical/ Anterior and Posterior
 Transverse-
Horizontal/ Superior and
Inferior “Cross Section”
Organ Systems
 Do
you remember how many organ
systems there were?
11 Organ Systems
Integumentary System
 Function:



Protects deeper tissue from injury
Pain/ Pressure receptors
Sweat/ Oil Glands
• Major Organs
• Hair
• Skin
• Nails
Skeletal System
 Function:



Protects and Supports body organs
Framework for muscles to Pull on
Stores Minerals
• Major Organs
• Bones
• Joints
Muscular System
 Function:



Allows manipulation of environment
Locomotion, facial expressions, maintain
posture
Produce Heat
• Major Organs
• Muscles
Nervous System
 Function:


Control System
Responds by activating appropriate
muscles and glands
• Major Organs
• Brain
• Nerves
• Spinal Cord
Endocrine System
 Function:

Glands secrete hormones that regulate
growth, reproduction, and nutrient use
• Major Organs
•
•
•
•
Thyroid gland
Thymus
Pancreas
ovary
•
•
•
•
Testis
Adrenal Gland
Pineal Gland
Pituitary Gland
Cardiovascular System
 Function:



Blood Vessels transport blood
Carries oxygen, Carbon dioxide, nutrients,
and wastes
Heart pumps the blood
• Major Organs
• Blood Vessels
• Heart
Lymphatic (Immune)
 Function:


Picks up fluid leaked from the blood vessels
and returns it to the blood
Houses White Blood Cells that are involved
in immunity (fighting diseases and sickness)
• Major Organs
• Red Bone Marrow
• Thymus
• Lymphatic Vessels
• Spleen
• Thoracic duct
• Lymph Nodes
Urinary System
 Function:



Eliminates nitrogenous waste
Regulates Water
Electrolyte and acid-base balance of
blood
• Major Organs
•
•
•
•
Kidney
Ureter
Urinary Bladder
Urethra
Respiratory System
 Function:


Keeps the blood supplied with oxygen and
removes carbon dioxide
Gas exchange for the lungs
• Major Organs
• Nasal Cavity
• Pharynx
• Larynx
• Trachea
• Lung
• Bronchus
Digestive System
 Function:


Breaks down food into absorbable units
Indigestible food is eliminated out of body
• Major Organs
• Oral Cavity
• Esophagus
• Liver
• Stomach
•
•
•
•
Small Intestine
Rectum
Anus
Large Intestine
Reproductive System
 Function:

Production of Offspring
 Testes-
Produce sperm and male sex
hormones
 Ovaries- produce eggs and female sex
hormones
Major Organs – MALE
 Prostate
Gland
 Penis
 Testes
 Scrotum
 Ductus
deferens
Major Organ- Female
 Mammary
Glands
 Ovary
 Uterus
 Vagina
 Uterine
tube
Dorsal Body Cavity
 Protects
 There


the fragile nervous system organs
are 2 subdivisions
Cranial- encases the brain
Vertebral- encloses the spinal cord
Ventral Body Cavity
 More
 Also


anterior and larger body cavity
has 2 subdivisions
Thoracic- (superior) surrounded by ribs and
muscles
Abdominopelvic- (inferior)
Thoracic
 Pleural
Cavity- each houses a lung
 Mediastinum-
contains the pericardial
cavity – encloses the heart
 and
surrounds the thoracic organs such as
esophagus, trachea, and others
Abdominopelvic
 Abdominal
Cavity- stomach,
intestines, spleen, liver and other
organs
 Pelvic
Cavity- bladder, some
reproductive organs, and rectum