1. An Introduction to the Structure and Function of the Body
Ms. Ryan
MCATC
Body Structure & Functions

2. OBJECTIVES Define the terms anatomy & physiology
List the levels of organization of the body
Define the term anatomical position
List & define the principal terms and sections (planes) used in describing the body & the relationship of body parts to one another
List the 9 abdominopelvic regions and the abdominopelvic quadrants

3. OBJECTIVES
List the major cavities of the body and subdivisions of each
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

4. Overview of Anatomy and Physiology
Anatomy – the study of the structure of body parts and their relationships to one another
Physiology – the study of the function of the body’s structural machinery

5. Levels of Structural Organization
Smooth muscle cell
Molecules
Cellular level Cells are made up of molecules 2
Atoms 1
Chemical level Atoms combine to form molecules
Smooth muscle tissue
Heart 3
Tissue level Tissues consist of similar types of cells
Cardiovascular system
Blood vessels
Epithelial tissue
Smooth muscle tissue
Blood vessel (organ) 6
Organismal level The human organism is made up of many organ systems
Connective tissue 4
Organ level Organs are made up of different types of tissues 5
Organ system level Organ systems consist of different organs that work together closely
Figure 1.1

6. Levels of Structural Organization
Chemical – atoms combined to form molecules
Cellular – cells are made of molecules
Tissue – consists of similar types of cells
Organ – made up of different types of tissues
Organ system – consists of different organs that work closely together
Organism – made up of the organ systems

7. Anatomical Position Body erect Feet slightly apart
Palms facing forward
Thumbs point away from body
When the body is not in anatomical position it may be:
Supine-lying face up
Prone-lying face down
Figure 1.7a

8. Directional Terms
Superior and inferior – toward and away from the head, respectively
Anterior and posterior – toward the front and back of the body
Medial, lateral, and intermediate – toward the midline, away from the midline, and between a more medial and lateral structure

9. Directional Terms
Proximal and distal – closer to and farther from the origin of the body
Superficial and deep – toward and away from the body surface

10. Directional Terms
Table 1.1

11. Directional Terms
Table 1.1

12. Directional Terms

13. Directional Terms

14. Directional Terms

15. Body Planes Sagittal – divides the body into right and left parts
Midsagittal or medial – sagittal plane that lies on the midline
Frontal or coronal – divides the body into anterior and posterior parts
Transverse or horizontal (cross section) – divides the body into superior and inferior parts

16. Body Planes
Figure 1.8

17. Body Planes and Sections
Coronal (frontal) plane - Lies vertically and divides body into anterior and posterior parts
Median (midsagittal) plane - Specific sagittal plane that lies vertically in the midline

18. Body Planes and Sections
Transverse plane - runs horizontally and divides body into superior and inferior parts

19. Body Cavities
Figure 1.9a

20. Body Cavities Cranial cavity is within the skull and encases the brain
Dorsal cavity protects the nervous system, and is divided into two subdivisions
Cranial cavity is within the skull and encases the brain
Vertebral cavity runs within the vertebral column and encases the spinal cord
Ventral cavity houses the internal organs (viscera), and is divided into two subdivisions:
Thoracic
Abdominopelvic cavities

21. Body Cavities Ventral body cavity subdivided into: Thoracic cavity
Two lateral parts each containing a lung surrounded by a pleural cavity
Mediastinum – contains the heart surrounded by the pericardial sac

22. Body Cavities Ventral body cavity
2. Abdominopelvic cavity – divided into two parts
Abdominal cavity – contains the liver, stomach, kidneys, and other organs
Pelvic cavity – contains the bladder, some reproductive organs, and rectum

23. Body Cavities

24. Abdominal Regions
Divide the abdomen into nine regions

25. Abdominal Quadrants Divide the abdomen into four quadrants
Right upper and left upper quadrants
Right lower and left lower quadrants

26. Body Regions Axial – head, neck, and trunk
Appendicular – appendages or limbs

27. Homeostasis
Homeostasis is the ability to maintain a relatively stable internal environment in an ever-changing outside world
The internal environment of the body is in a dynamic state of equilibrium
Chemical, thermal, and neural factors interact to maintain homeostasis

28. Homeostatic Imbalance
Disturbance of homeostasis or the body’s normal equilibrium
Overwhelming of negative feedback mechanisms allowing destructive positive feedback mechanisms to take over-possible disease, death