CHAPTER 1
HUMAN ANATOMY & PHYSIOLOGY
The Human Body
An Orientation


Anatomy – study of the structure
and shape of the body and its parts
Physiology – study of how the body
and its parts work or function
Anatomy
Levels of Study

Gross Anatomy – when we look at our
own body
• Large structures
• Easily observable

Microscopic Anatomy – when we look at
cells and tissues of the body
• Very small structures
• Can only be viewed with a microscope
Relationship between Anatomy
and Physiology

The parts of your body form a wellorganized unit, and each of those
parts has a job to do to make the
body operate as a whole.
Levels of Structural
Organization

Chemical Level
• Simplest level
• Atom – tiny building blocks of matter
• Atoms combine to form molecules.
Levels of Structural
Organization

Cellular Level
• Cell – the smallest units of all living
things
• Cells are made up of molecules.
Levels of Structural
Organization

Tissue Level
• Tissues consist of similar types of cells
that have a common function.
Levels of Structural
Organization

Organ Level
• Organs are made up of different types
of tissues.
Levels of Structural
Organization

Organ System Level
• Organ systems consist of different
organs that work together closely.
Levels of Structural
Organization

Organism Level
• Highest level of structural organization.
• Human organisms are made up of 11
organ systems.
Organ System Overview

Integumentary System
• Organ – skin
• Functions:




Forms the external body covering
Protects deeper tissue from injury
Synthesizes vitamin D
Location of cutaneous nerve receptors
Organ System Overview

Skeletal System
• Organs – cartilages, joints, and bones
• Functions:




Protects and supports body organs
Provides muscle attachment for
movement
Site of blood cell formation
Stores minerals
Organ System Overview

Muscular System
• Organs – skeletal muscles
• Functions:



Allows locomotion
Maintains posture
Produces heat
Organ System Overview

Nervous System
• Organs – brain, spinal cord, and nerves
• Functions:



Fast-acting control system
Responds to internal and external change
Activates muscles and glands
Organ System Overview

Endocrine System
• Organs – pituitary gland, thyroid gland,
pancreas, testis, ovary
• Functions:


Secretes regulatory hormones
Hormones responsible for growth,
reproduction, and metabolism
Organ System Overview

Cardiovascular System
• Organs – heart and blood vessels
• Functions:


Transports materials in the body through the
blood
Materials transported includes oxygen,
carbon dioxide, nutrients, and wastes
Organ System Overview

Lymphatic System
• Organs – lymph nodes
• Functions:



Returns fluids to blood vessels
Disposes of debris
Involved in immunity
Organ System Overview

Respiratory System
• Organs – nasal cavity, pharynx,
larynx, trachea, lungs
• Functions:


Keeps blood supplied with oxygen
Removes carbon dioxide
Organ System Overview

Digestive System
• Organs – mouth, esophagus, stomach,
intestines, rectum, anus
• Functions:



Breaks down food
Allows for nutrient absorption into blood
Eliminates indigestible material
Organ System Overview

Urinary System
• Organs – kidney and urinary bladder
• Functions:



Eliminates wastes
Maintains acid-base balance
Regulation of water and electrolytes
Organ System Overview

Reproductive System
• Organs:


Male – penis, testis, scrotum, seminal
vesicles, prostate gland
Female – mammary glands, ovary, uterus,
vagina
• Functions:

Production of offspring
Necessary Life Functions


Maintain Boundaries
Movement
• Locomotion – walking, swimming, etc.
• Movement of substances

Responsiveness
• Ability to sense changes and react

Digestion
• Break-down and delivery of nutrients
Necessary Life Functions

Metabolism
• Chemical reactions within the body
• Production of energy
• Making body structures

Excretion
• Elimination of waste from metabolic reactions

Reproduction
• Production of offspring

Growth
• Increasing cell size and number
Survival Needs

Nutrients
• Chemicals for energy and cell building
• Includes carbohydrates, proteins, lipids,
vitamins, and minerals

Oxygen
• Required for chemical reactions
Survival Needs

Water
• 60-80 % of body weight
• Single most abundant chemical substance in the
body
• Provides for metabolic reaction

Stable Body Temperature
• Must be maintained at around 98F

Atomospheric Pressure Must Be
Appropriate
• The force exerted on the surface of the body by
the weight of air
Homeostasis


Homeostasis = Maintenance of a
stable internal environment = A
dynamic state of equilibrium
Homeostasis must be maintained for
normal body functioning and to
sustain life.
Homeostatic Imbalance


A disturbance in homeostasis
resulting in disease
As we age, our body organs become
less efficient, and our internal
conditions become less and less
stable.
Maintaining Homeostasis


The body communicates through neural
and hormonal control systems
Control Mechanism:
• The receptor responds to changes in the
environment and sends information to the
control center (brain).
• The control center determines the set point
(98.6) and determines the appropriate
response.
Feedback Mechanisms

Negative Feedback
• Includes most homeostatic control
mechanisms
• Works like a household thermostat
• Your body’s thermostat is located in a
part of the brain called the
HYPOTHALAMUS
• It shuts off the original stimulus, or
reduces its intensity
Feedback Mechanisms

Positive Feedback
• Increases the original stimulus or
disturbance
• In the body this only occurs in blood
clotting and birth of a baby
The Language of Anatomy


Special terminology is used to
prevent misunderstanding
Exact terms are used for:
• Position
• Direction
• Regions
• Structures
Orientation and Directional
Terms


Anatomical Position – the body is
erect with the feet parallel and the
arms hanging at the sides with the
palms facing forward
Table 1.1 on page 12 – go over
these
Body Landmarks


Anterior Landmarks on page 13
go over these, but students have a
copy of these terms
Posterior Landmarks on page 13
go over these, but students have a
copy of these terms
Body Planes – 3 types (page
15)

Sagittal Section
• A cut made along a lengthwise plane of
the body – divides the body into right
and left parts
• Midsagittal Section

When the cut is made down the middle of
the body and the right and left parts are
equal in size
Body Planes – 3 types (page
15)

Frontal Section
• A cut made along a lengthwise plane - divides
the body into anterior and posterior parts
• Also known as Coronal Section

Transverse Section
• A cut made along a horizontal plane – divides
the body into superior and inferior parts
• Also known as Cross Section
Body Cavities

Dorsal Body Cavity – 2 subdivisions
• Cranial Cavity – the space inside the
bony skull; contains the brain
• Spinal Cavity – extends from the cranial
cavity nearly to the end of the vertebral
column
Body Cavities

Ventral Body Cavity – contains all the
structures within the chest and abdomen
• Thoracic Cavity – contains the lungs and heart;
separated from the rest of the ventral cavity by
a dome-shaped muscle = DIAPHRAGM
• Abdominopelvic Cavity – 2 smaller subdivisions:


Abdominal Cavity – contains the stomach, liver, and
intestines
Pelvic Cavity – contains the reproductive organs,
bladder, and rectum
Abdominopelvic Quadrants

4 quadrants (page 17, figure 1.8A)
Abdominopelvic Regions

9 regions (page 17, figure 1.8B)
Abdominopelvic Major Organs

page 17, figure 1.8C