1. Homeostasis and Pathology Unit 1

2. Homeostasis The process by which the internal environment of the body is kept relatively stable despite changes in the world around us.

3. Feedback loops Positive feedback loops: Provide an increased reaction when the feedback is received. ◦ (i.e. Uterine contractions provide feedback to stimulate even greater uterine contractions during childbirth.) ◦ Continue to move away from homeostasis until function is reached. Negative feedback loops: Provide an opposite reaction when the feedback is received. ◦ (i.e. Sweating and Shivering to maintain a stable temperature.) ◦ Promote homeostasis!

4. Feedback Loops Assignment For each given loop described on the worksheet… ◦ Label whether it is a positive or negative feedback loop. ◦ Underline or highlight the key phrases within each description that support your claim. ◦ Don’t stress to much about the actual content of these loops—we will study them in greater detail when we study those systems.

5. Disease A condition in which homeostasis is disrupted and normal function is impaired. There are 4 types ◦ Congenital ◦ Immunological ◦ Metabolic ◦ Neoplastic

6. Congenital Diseases Conditions that arise before birth

7. Immunological Diseases that are caused by an invading pathogen or allergen that elicits a response form the immune system. ◦ Viral ◦ Bacterial ◦ Allergies ◦ Asthma

8. Metabolic Diseases that affect the cellular energy balance directly. ◦ Diabetes ◦ Physical Trauma ◦ Endocrine disturbances

9. Neoplastic Abnormal cellular growth and reproduction ◦ Tumors ◦ Cancer