2. Homeostasis Stable internal environment Involves 1. Receptor – senses stimulus 2. Control Center – receives and processes info 3. Effector – responds to stimulus 4. Pathways 1. Afferent (receptor to control center) 2. Efferent (control center to effector)

4. Homeostasis as Room Temp 1. Thermometer (receptor) notices higher room temp (stimulus) 2. Thermostat (control center) receives and processes info 3. Air conditioner (effector) turns on

6. Homeostatic Feedback Negative Feedback: a variation outside normal limits triggers an automatic response that corrects the situation ie: body temperature, hormone regulation, blood pressure Positive Feedback: the initial stimulus produces a response that reinforces that stimulus ie: clotting, birth contractions, lactation

7. Negative Feedback

8. Negative Feedback – Temp. Rises

9. Negative Feedback – Temp. Lowers

10. Negative Feedback

11. Positive Feedback

12. Review Feedback with Whiteboards Define feedback Define negative feedback Define positive feedback Compare and contrast negative and positive feedback Which type of feedback is more common List examples of negative feedback List examples of positive feedback Draw an example of feedback regarding temperature

13. Homework Chapter 1 Coloring Workbook Number 10, 24 and 25 from An Introduction to Anatomy and Physiology – Chapter 1 Objectives 5-6