1. Chapter 4
Body Organization and Homeostasis

2. The Organization of the Human Body Increases in Complexity from Cells to Organ Systems
Tissues form organs that often work together in organ systems
Organ systems: Groups of organs that work together to perform a common function

3. FIGURE 4.6 part 2
The major organ systems of the human body

4. FIGURE 4.6 part 3
The major organ systems of the human body

5. FIGURE 4.6 part 4
The major organ systems of the human body

6. FIGURE 4.6 part 5
The major organ systems of the human body

7. FIGURE 4.6 part 6
The major organ systems of the human body

8. FIGURE 4.6 part 8
The major organ systems of the human body

9. FIGURE 4.6 part 9
The major organ systems of the human body

10. FIGURE 4.6 part 10
The major organ systems of the human body

11. FIGURE 4.6 part 11
The major organ systems of the human body

12. FIGURE 4.7 part 2
Body cavities. The internal organs are suspended in body cavities that protect the organs and allow organs to slide past one another as the body moves. Ventral means toward the abdomen, and dorsal means toward the back.

13. Homeostasis Maintains Relatively Constant Internal Environment
Homeostasis is maintained by negative feedback mechanisms
Example: The regulation of body temperature

14. Homeostasis
A negative feedback mechanism receives information from a receptor that detects a change in the internal or external environment…

15. FIGURE 4.12
The components of a homeostatic control system

16. Homeostasis
Then a control center such as the brain sends out a response and the effector carries out the response returning the system to homeostasis again

17. Homeostasis
The thermostat for the body is located in the hypothalamus

18. Homeostasis
Hyperthermia, abnormally elevated body temperature, and hypothermia, abnormally low body temperature, are both life-threatening conditions that result when this mechanism fails.

19. FIGURE 4.13
The homeostatic regulation of body temperature

20. Homeostasis is usually maintained by:
Positive feedback mechanisms
Neutral forces
Negative feedback mechanisms
Magic
Witch doctors