Major Concepts of
Anatomy and
Physiology
Part 1: Organization of the
Human Body
What is A&P?

Anatomy:
 The

study of the structure of the human body.
Physiology:
 The
study of the function of the human body.
Subdivisions of Anatomy
Gross Anatomy: Studies structures visible
to naked eye.
 Histology: Studies structure of tissues
visible through a microscope.
 Neuroanatomy: Studies the structures of
the human nervous system.
 Embryology: Studies the development of
human embryos.
 Radiographic Anatomy: Studies the
structures visible via x-ray.

Subdivisions of Physiology
Neurophysiology: Studies the function of
the human nervous system
 Cardiophysiology: Studies the human
cardiovascular system.
 Immunology: Studies the structure &
function of the immune system.
 Endocrinology: Studies the function of
hormones and their effects.
 Pathophysiology: Studies the changes
brought on by disease and aging.

Homeostasis

Homeostasis:
 The
healthy internal balance of the human
organism.
 The body will always attempt to return to
homeostasis if change occurs.

Feedback Systems are used to
maintain homeostasis.
 E.g.
blood glucose, body temperature, etc.
 Major fluctuations may indicate a problem!
Feedback Mechanisms

Negative Feedback Mechanisms:
 Maintains
the body condition in question
within a small “normal range” of its set point.

Examples:
 Blood
sugar range (80-120mg/ml)
 Body Temperature (36.5-38*C)
 Blood pH
 Your thermostat!
Feedback Mechanisms

Positive Feedback Mechanisms:
 Strengthens
of reinforces a change where the
response to a stimulus actually increases the
original stimulus. Produces a fairly rapid
change.

Examples:
 Labor
Hierarchy of Complexity

6 Levels of the Hierarchy
 Chemical
Level
 Cellular Level
 Tissue Level
 Organ Level
 System Level
 Organism Level

Moves from simple to complex.
Chemical Level
The atoms and molecules that make up
the cells of the body.
 Subatomic Particles:
 Smaller
than atoms
 Include protons, neutrons & electrons

Atoms:
 The
smallest unit of the elements
 Formed by combinations of the subatomic
particles
Chemical Level

Elements:
 Fundamental
substances composed of atoms
 Chemically alike &cannot be separated into smaller
substances by typical methods
 Include Oxygen, hydrogen, carbon, & nitrogen

Molecules:
 Composed
of groups of atoms
 Includes things like Glucose & Macromolecules

Macromolecules:
 Composed
of hundreds or thousands of molecules
 Includes proteins, fats, carbohydrates, DNA, RNA
Cellular Level

Organelles:
 Microscopic
structures contained inside cells
 Carry out individual functions
 Include Mitochondria, endoplasmic reticulum,
lysosomes

Cells:
 The
basic building block of all organic
organisms (living things)
Tissue Level

Tissue:
 A mass
of similar cells that perform the same
specific function
 FOUR PRIMARY TISSUES
Epithelium Tissue
 Connective Tissue
 Muscle Tissue
 Nervous Tissue

Organ Level

Organ:
 Structure
composed of two or more separate
tissue types working together to carry out a
particular function
 Distinct gross anatomical boundaries
 Include stomach, heart, brain, etc.
System Level

Organ System:
 A group
of organs connected together to
accomplish a unique collective function
 Example: Digestive system
Separate organs include the esophagus, stomach,
small & large intestines
 Functions include digestion, absorption, and
excretion

Organism Level

Organism:
 A single
complete individual
 Composed of a number of different organ
systems
 11 Systems in the Human
Integumentary
Skeletal
Muscular
Cardiovascular
Nervous Endocrine
Respiratory
Digestive Lymphatic
Reproductive
Urinary
Six Characteristics of Living
Organisms
1.
Metabolism: All chemical reaction occurring
within living cells.
1.
2.
2.
3.
Anabolism: Synthesis reactions to combine small
molecules to form larger ones. Requires an input of
energy.
Catabolism: Reactions reduce large, complex
substances into simpler ones. Releases energy.
Growth: An increase in size through division
and/or enlargement of cells.
Differentiation: The process of developing
unspecialized cells into specialized cells with
specific structure and function.
Six Characteristics of Living
Organisms
1.
2.
3.
Movement: Includes motion of a body
part or materials through the body.
Responsiveness: The ability to detect
and respond to changes in the
environment.
Reproduction: The process of
producing a new organism or forming
new cells.
Anatomical Position


The anatomical position is the
standard reference position for
A&P.
Requires a person to…
 Stand
with feet flat on the floor
 Arms at the sides
 Palms, face, eyes, and feet face
forward

All descriptions assume the
body is in this position.
Directional Terms
Superior: Toward the top of the head
 Inferior: Below or toward the feet
 Anterior or Ventral: Front
 Posterior or Dorsal: Back
 Medial: Toward the midline/midsagittal
plane
 Lateral: Away from the midline
 Proximal: Closer to midline or the point of
limb attachment

Directional Terms
Distal: Farther away from the midline or
point of limb attachment
 Superficial: Closer to the surface of the
body
 Deep: Farther from the surface of the
body

Anatomical Planes

Sagittal Plane: Extends vertically from
head to toes; divides the body into left and
right portions.
 Midsagittal
Median Plane: Passes exactly
through midline (middle) of the body; divides
the body into equal halves.
 Parasagittal Plane: Any sagittal plane that
passes through the body to the left or right of
the midline; divides the body into unequal left
& right portions.
Anatomical Planes

Frontal Coronal Plane: Vertically oriented
plane
 At
right angles perpendicular to the sagittal
plane
 Divides the body into a front (anterior) and
back (posterior) portion
Anatomical Planes

Transverse Plane: Passes through the
body horizontally
 Perpendicular
to the long axis of the body
 Divides the body into top (superior) and
bottom (inferior) portions.
 Typical plane of Computerized Tomography
(CT) scans
Anatomical Planes

Oblique Plane: Passes through the body
at an angle
 Between
the transverse plan and either a
sagittal or frontal plane.
Surface Anatomy

Axial Region: The area of the body
closest to the midline. Consists of..
 head
 neck
 Trunk
Thoracic region (chest above diaphragm)
 Abdominopelvic region (below diaphragm)

Surface Anatomy

Appendicular Region: Are of body farthest away from
the midline. Consists of the Appendages (upper and
lower limbs, extremities).












Brachium: Arm from shoulder to elbow
Antebrachium: Forearm from elbow to wrist
Carpus: Wrist area
Metacarpus: Hand between carpus & phalanges
Manus: Hand
Digits (Phalanges): Fingers
Thigh: From hip to knee
Crus (Shank): From knee to ankle
Tarsus: Ankle between leg and metatarsus
Metatarsus: Foot from ankle to toes.
Pes: The foot
Digits (Phalanges): The toes
Body Cavities

Dorsal Cavity: Lined by the meninges (dura mater,
arachnoid mater, and pia mater).



Ventral Cavity



Cranial Cavity: Contains the brain; enclosed in the skull.
Vertebral or Spinal Cavity: Contains the spinal chord; enclosed
in the vertebral column.
Thoracic Cavity: Contains the heart, lungs, & upper digestive
system organs.
Abdominopelvic Cavity: Contains the stomach, liver,
gallbladder, spleen, pancreas, urinary bladder, small & large
intestine. Kidneys located BEHIND abdominopelvic cavity.
Organs located in these cavities are referred to as
viscera.
Abdominopelvic Cavity

4 Abdominopelvic Quadrants:
 Right
Upper Quadrant
 Left Upper Quadrant
 Left Lower Quadrant
 Right Lower Quadrant
Abdominopelvic Cavity

9 Abdominopelvic Regions
 Right Hypochondriac Region: Liver, gall bladder
 Epigastric Region: Liver, stomach, pancreas
 Left Hypochondriac Region: Stomach, spleen
 Right Lateral or Lumbar Region: Ascending colon,
gall
bladder
 Umbilical Region: Stomach, transverse colon, small
intestine, pancreas
 Left Lateral or Lumbar Region: Small intestine,
descending colon
 Right Inguinal or Iliac Region: Cecum, small intestine
 Hypogastric Region: Small intestine, rectum, urinary
bladder, reproductive organs
 Left Inguinal or Iliac Region: Small intestine, sigmoid colon