2. 5 Levels of Organization- 1) The body-2) Organ systems-

3. 3) Organ 4) Tissue muscle skin nerve

4. 5) Cell- Nerve cellRed blood cell Muscle cell

5. Homeostasis- internal stability or "steady state" maintained by the body. (27-3) 1) no matter what the external temperature is, we keep our internal temperature at _______. 98.6˚ F - When cold, you must use ________ to create heat through the process of shivering food -When too warm, we __________. sweat

6. 2) O 2 vs. CO 2 levels- job of the lungs and circulatory system. Information from brain sent to these organs by hormones to help balance O 2 vs. CO 2 hormones

7. 3.) protection from the external world- a.) skin- b.) Hair on head, nose, face c) nails d) mucus