1. An Introduction to the Structure and Function of the Body
Chapter 01
An Introduction to the Structure and Function of the Body

2. Organization of the Body, and Anatomical Position and Directions
Lesson 1.1
Organization of the Body, and Anatomical Position and Directions
Define the following terms: anatomy, physiology, and pathology.
Describe the scientific method.
List and discuss in order of increasing complexity the levels of organization of the body.
Define the term anatomical position.
List and define the principal directional terms and sections (planes) used in describing the body and the relationship of body parts to one another.

3. Introduction
Anatomy—study of structure of an organism and relationships of its parts (Dissection)
Physiology—study of functions of living organisms and their parts
Pathology—scientific study of disease

4. The Scientific Method

5. Structural Levels of Organization
Organization is the most important characteristic of body structure.
The body as a whole is a unit constructed of the following smaller units:
Atoms and molecules—chemical level
Cells—the smallest structural units; organizations of various chemicals
Tissues—organizations of similar cells working together
Organs—organizations of different kinds of tissues arranged for specific functions
Systems—organizations of many different kinds of organs working together for complex functions
Organism (body as a whole)-All systems working together

6. Structural Levels of Organization
Courtesy of Barbara Cousins.

7. Anatomical Position
Reference the position in which the body is standing erect with the feet slightly apart and arms at the sides with palms turned forward.
Anatomical position gives meaning to directional terms.

8. Copyright Kevin Patton, Lion Den Inc, Weldon Springs, MO.
Anatomical Position
Copyright Kevin Patton, Lion Den Inc, Weldon Springs, MO.

9. Anatomical Directions
Superior—toward the head, upper, above
Inferior—toward the feet, lower, below

10. Anatomical Directions
Anterior—front, in front of (same as ventral in humans)
Posterior—back, in back of (same as dorsal in humans)

11. Anatomical Directions
Medial—toward the midline of a structure
Lateral—away from the midline or toward the side of a structure

12. Anatomical Directions
Proximal—toward or nearest the trunk, or nearest the point of origin of a structure
Distal—away from or farthest from the trunk, or farthest from a structure’s point of origin

13. Anatomical Directions
Superficial—nearer the body surface
Deep—farther away from the body surface

14. Planes or Body Sections
Sagittal plane—lengthwise plane that divides a structure into right and left sections
Midsagittal—sagittal plane that divides the body into two equal halves
Frontal (coronal) plane—lengthwise plane that divides a structure into anterior and posterior sections
Transverse plane—horizontal plane that divides a structure into upper and lower sections

15. Directions and Planes of the Body & Tissues
Courtesy of Barbara Cousins.

16. Lesson 1.2
Body Sections, Cavities, and Regions; and the Balance of Body Functions
List the major cavities of the body and the subdivisions of each, including the nine abdominopelvic regions and the abdominopelvic quadrants.
Discuss and contrast the axial and the appendicular subdivisions of the body. Identify a number of specific anatomical regions in each area.
Explain the meaning of the term homeostasis, and give an example of a typical homeostatic mechanism.

17. Body Cavities Ventral cavity Thoracic cavity
Mediastinum—midportion of thoracic cavity; heart and trachea located in mediastinum
Pleural cavities— right lung located in right pleural cavity; left lung in left pleural cavity

18. Courtesy of Rolin Graphics.
Body Cavities
Courtesy of Rolin Graphics.

19. Body Cavities Ventral cavity Abdominopelvic cavity
Abdominal cavity— contains stomach, intestines, liver, gallbladder, pancreas, and spleen
Pelvic cavity— contains reproductive organs, urinary bladder, and lowest part of intestine
Abdominopelvic regions
Nine regions
Four quadrants

20. Quadrants and Regions of Abdominopelvic Cavity
Courtesy of Barbara Cousins.

21. Body Cavities Dorsal cavity Cranial cavity contains the brain
Spinal cavity contains the spinal cord

22. Organs of the Major Body Cavities

23. Body Regions Axial region— head, neck, and torso or trunk
Appendicular region— upper and lower extremities

24. Axial & Appendicular Divisions of the Body

25. The Balance of Body Functions
Survival of the individual and of the genes that make up the body is of the utmost importance.
Survival depends on the maintenance or restoration of homeostasis (relative constancy of the internal environment).
The body uses negative feedback loops and, less often, positive feedback loops to maintain or restore homeostasis.
Feedback loops involve a sensor, a control center, and an effector.

26. The Body's Internal Environment

27. Negative Feedback Loops

28. Positive Feedback Loop

29. The Balance of Body Functions
All organs function to maintain homeostasis.
Ability to maintain balance of body functions is related to age:
Peak efficiency occurs during young adulthood; diminishing efficiency occurs after young adulthood.

30. Studies of the Human Body (cont.)
Body Systems (Organized by Function)
Protection, support, and movement
Integumentary
Skeletal
Muscular
Coordination and control
Nervous
Endocrine

31. Studies of the Human Body (cont.)
Body Systems (Organized by Function) (cont.)
Circulation and immunity
Cardiovascular
Lymphatic
Energy supply and fluid balance
Respiratory
Digestive
Urinary
Production of offspring
Reproductive

32. Effects of Aging Gradual changes occur in all body systems.
Some changes are harmless.
Wrinkles and gray hair
Some changes may result in injury and disease.
Decreased kidney function
Loss of bone mass
Formation of deposits within blood vessels

34. Key Terms anabolism intracellular fluid anatomic position metabolism
anatomy
negative feedback
catabolism
organ
cell
pathology
disease
physiology
extracellular fluid
system
homeostasis
tissue

35. Word Anatomy (cont.) Word Part Meaning Example
Studies of the Human Body
dis-
apart, away from
To dissect is to cut apart.
-logy
study of
Radiology is the study and use of radioactive substances.
path/o
disease
Pathology is the study of disease.
physi/o
nature, physical
Physiology is the study of how the body functions.
-tomy
cutting, incision of
Anatomy

36. Word Anatomy (cont.) Word Part Meaning Example Metabolism ana-
upward, again, back
Anabolism is the building up of simple compounds into more complex substances.
cata-
down
Catabolism is the breakdown of complex substances.
extra-
outside of, beyond
Extracellular fluid is outside the cells.
home/o-
same
Homeostasis is the steady state (sameness) within an organism.
intra-
within
Intracellular fluid is within a cell.
stat, -stasis
stand, stoppage, constancy
In homeostasis, “-stasis” refers to constancy.