Introduction to Human Body

1. Chapter 1
Introduction to
the Human Body
Joel G. Soria, MD

2. Anatomy
• The scientific discipline that investigates the structure of the
body.
• “Anatomy” means to dissect, or to cut apart and separate, the
parts of the body.
• Covers: Structure of the body, microscopic organization,
processes by which they develop
• Examines the relationship of the structure of the body part
and its function.

3. Types of Anatomy
• systemic: studies body systems
• regional: studies body regions (medical schools)
• surface: studies external features, e.g., bone projections
• anatomical imaging: using technologies (x-rays, ultrasound,
MRI)

4. • The study of function in living organisms.
• It explores the mechanisms by which the organisms control their
internal environments regardless of what happens in the outside
(or external) environment.
• Major Goals of Physiology:
• Understand and predict the body’s response to stimuli
• Understand how the body maintains conditions within a
narrow range of values in a presence of a continually changing
environment.
Physiology

5. Importance of Anatomy and Physiology
understand how the body:
responds to stimuli
• environmental change
• environmental cues
• diseases
• injury
maintains stable, internal conditions despite continually changing
environment

6. STRUCTURAL AND
FUNCTIONAL ORGANIZATION

7. Structural and functional organization
Six levels from chemical to organism:
1. chemical: smallest level
- atoms, chemical bonds, molecules
2. cellular:
- cells: basic units of life
- compartments and organelles
e.g., mitochondria, nucleus, ribosomes,
cytoplasm

8. Structural and functional organization
3. tissues:
- group of cells with similar structure and
function plus extracellular substances they
release
- four broad types:
epithelial muscular
connective nervous
4. organs:
- two or more tissue types acting together
to perform function(s)
- e.g., stomach, heart, liver, ovary, bladder

9. Structural and functional organization
5. organ system:
- group of organs contributing to some
function
- e.g., digestive system, reproductive
system
6. organism:
- all organ systems working together
- includes associated microorganisms
such as intestinal bacteria

12. Characteristics of Life
organization:
• functional interrelationships between parts
metabolism:
• sum of all chemical and physical changes sustaining an organism
• ability to acquire and use energy in support of these changes
responsiveness
• ability to sense and respond to environmental changes
• includes both internal and external environments

13. Characteristics of Life
growth
• can increase in size
• size of cells, groups of cells, extracellular materials
development
• changes in form and size
• changes in cell structure and function from generalized to
specialized - differentiation
reproduction
• formation of new cells or new organism
• generation of new individuals
• tissue repair

14. Homeostasis
homeostasis
- maintenance of constant internal environment
variables: measures of body properties that may
change in value
Examples of variables:
body temperature blood glucose levels
heart rate blood cell counts
blood pressure respiratory rate
set point: normal, or average value of a variable

15. normal range: normal extent of increase or decrease around a set point
example: over time, body temperature fluctuates around a set point of
about 98.6o

16. 16
negative feedback
- mechanism that maintains homeostasis
- negative feedback response:
detection: of deviation away from set point and...
correction: reversal of deviation toward set point and
normal range
Homeostasis

17. 17
Components of Negative Feedback
1 receptor:
detects changes in variable
2 control center:
- receives receptor signal
- establishes set point
- sends signal to effector
3 effector:
- directly causes change in variable
3

18. Terminology of Body Planes
anatomical position:
- person standing erect with face and
palms forward
- all relational descriptions based on the
anatomical position, regardless of body
orientation
supine:
person lying face up
prone:
person lying face down
superior

19. Prone Position
Supine Position

20. Superior Inferior

21. Anterior Posterior
(Ventral) (Dorsal)

22. Medial Lateral

23. 23
proximal: close to point of
attachment
distal: far from point of
attachment
superficial: structure close to
the surface
deep: structure toward the
interior of the body
4
Deep
Superficial

24. Proximal Distal

25. Deep Superficial