This document provides an overview of human anatomy and physiology. It defines anatomy and physiology, and explains that anatomy is the study of the structure of body parts while physiology is the study of how body parts function. It then describes the hierarchical organization of the human body from chemicals to cells to tissues to organs to organ systems and organisms. Each level of organization is defined. The key organ systems and their functions are also outlined.
1. Chapter 1:
Organization of
the Body
Virtuvian Man by Leonardo Da Vinci is one
of the most famous anatomical drawings in history.
2. Anatomy and Physiology
Anatomy: branch of
science dealing with the
form and structure of
body parts.
Physiology: branch of
science dealing with the
study of body functions.
Anatomy and physiology
are closely related
because an organ’s
structure is determined by
its function.
4. Were you right?
• Digestion: physiology
• Stomach: anatomy
• Blood pressure: physiology
• Heart: anatomy
• Muscle: anatomy
• Exercise: physiology
Remember: If the term is related to structure (how it is
constructed) it is anatomy.
If it is related to function (job) it is physiology.
5. Organization of Body Parts
Chemicals Cells Tissues Organs
• The chemicals are the smallest Organ
level of organization. The organism systems
is the largest level of organization.
Organism
6. Chemicals
• Atoms: The smallest part of elements.
Common atoms in humans include
carbon, hydrogen, oxygen, and
nitrogen.
1 atom of hydrogen
1 atom of oxygen
• Molecules: Chemically joined atoms.
Example: H2O (one molecule of water)
is made of two atoms of hydrogen and
one atom of oxygen.
1 molecule of H2o
7. Chemicals Continued…
• Macromolecules: Large
molecules made of
chemically combined
smaller molecules.
• Example: molecules of
amino acids join together to
form proteins. DNA is also a
macromolecule.
DNA model
8. Cells
Red blood cells
• The smallest unit of life.
Red blood cells carry
oxygen.
• Organelles are small
structures within cells
that perform specific
functions within the
cell. Mitochondria are
the places where
energy is released.
Mitochondrion
9. Tissues and Organs
• Tissues are composed of similar
cells and perform a specific
function. Cardiac muscle makes
the heart contract.
Cardiac muscle
Organs are composed of several
types of tissue and perform a
specific function. The heart
Moves blood throughout the body.
Normal human heart
10. Organ Systems and Organisms
• Organ systems are
composed of several
organs and perform a
specific function.
• An organism has many
organ systems working
together to keep it alive.
Blood flow through the
cardiovascular system.
11. Anatomical Terms
• Understanding them assumes
the body is in anatomical
position (standing erect, face
forward, arms at the sides and
palms and toes directed
forward).
12. Relative Positions
• Superior: above another part
• Inferior: below another part
• Anterior (ventral): toward the front
• Posterior (dorsal): toward the back
13. Planes and Sections of the Body
• Sagital plane:
divides the body in
half vertically.
• Transverse plane:
divides the body in
half horizontally.
• Frontal plane:
divides the body in
half lengthwise into
anterior and
posterior sections.
14. Regions of the body
• Cephalic: head
• Cervical: neck
• Thorax: chest
• Abdomen: stomach
area
• Limbs: arms and legs
20. Skeletal
• Consists of bones,
cartilage, and
ligaments.
• Functions to protect
organs, provide
support, production
of blood cells.
21. Muscular System
• Consists of skeletal,
cardiac, and smooth
muscle.
• Functions in the
movement of the
body.
22. Nervous System
• Consists of the brain,
spinal cord, and nerves.
• Functions to conduct
nerve impulses to and
from the brain thus
providing the organism
with information about
its environment and
internal conditions.
23. Endocrine System
• Consists of
hormonal glands
that secrete
chemicals that serve
as messengers
between body parts.
• Functions with
nervous system to
maintain a relatively
constant internal
environment.
24. Circulatory System
• Consists of heart
and blood vessels.
• Functions to carry
nutrients and
oxygen to the cells
and remove waste
products to be
excreted.
25. Respiratory System
• Consists of the
lungs and the
associated airways.
• Functions to bring
oxygen into the
lungs and to remove
carbon dioxide from
the lungs.
26. Digestive System
• Consists of the
mouth, esophagus,
stomach, small and
large intestine and
accessory organs.
• Functions to receive
food and digest it
into nutrient
molecules.
27. Urinary System
• Consists of the
kidneys and
bladder.
• Functions to rid the
body of nitrogenous
wastes and helps
regulate the fluid
level and chemical
content of blood.
28. Reproductive System
• Consists of different
organs in males and
females.
• Functions to ensure
the survival of the
species by allowing
organisms to
reproduce.
29. Homeostasis
• Mechanisms that keep the internal
environment relatively stable.
• One of the fundamental characteristics of
living things.
• All the bodies organ systems contribute to
homeostasis.
• Controlled by negative feedback
mechanisms.
• Disease results when these mechanisms
break down.
30. Negative Feedback Mechanisms
• Requires a receptor that detects when levels
are unacceptable and as a result triggers a
response.
• Also requires an effector that brings about a
response that negates the original conditions
that stimulated the receptor.
• Most homeostatic regulatory mechanisms
involve negative feedback.
31. Body Temperature Control
• Control of our body temperature involves a
negative feedback loop.
• Control center in brain (hypothalamus) functions
as the thermostat whose set point is 37 degrees
Celsius.
• When body temperature increases heat loss is
increased by sweating and increased blood flow
to skin until body temperature returns to normal.
• See text p.12 for an illustration of this concept.
