1. Announcements Lab this week: Frog Reflexes –Review information on lab webpage Friday Quiz –Topics Thermoregulation and Glucose Homeostasis and Frog Reflexes –Format Powerpoint slides on screen Multiple-multiple choice: choose all correct responses Fill in the blank About 10 questions

2. The Issues How do cells “know” which fuel to “burn?” How do cells “know” when to synthesize glycogen or lipids and when to break down glycogen or lipid? What is responsible for the transitions from the absorptive and post-absorptive states? How does glucose get into “sinks?”

3. Activates some enzymes, inactivates others GLUT-4 Peptide hormone Exercise via an undescribed mechanism + T1DM =beta cells fail to produce adequate insulin (5%) T2DM = target cells “resistant” (less responsive) to insulin ↑ plasma glucose →↑insulin secretion→↑glucose uptake into cells →↓ plasma glucose

4. Fig. 16.07 Identify sensors, afferent pathway, integrator, efferent pathway, effectors How is insulin secretion affected if plasma glucose is lower than set point? Which cell types have insulin receptors?

5. Fig. 16.01 =sink Absorptive Phase Neurons don’t have insulin receptors, but do have Glucose transporters (not GLUT-4) =GLUT-4

7. Absorptive Phase Post-Absorptive Phase

8. ? The Integrator integrates multiple inputs Glucose uptake, Storage, Lipogenesis WHY?

9. Another hormone that regulates plasma glucose concentration Glucagon prevails during post- absorptive phase Transition from absorptive to post- absorptive phase?

10. Fig. 16.10 EPI, yet another horomone in glucose homeostasis

11. Glucose-counterregulatory controls (oppose effects of insulin) Glucagon Epinephrine Cortisol (permissive effect) Growth hormone (permissive effect)

12. Who Cares?

13. A Case Study On our website at http://webs.wofford.edu/davisgr/bio342/oggt.htm

14. Oral Glucose Tolerance Test Overnight fast, no beverages other than water Fasting blood sample Ingest 75 grams glucose Blood samples every 0.5 hours for 3-5 hours Plot plasma glucose concentration over time Compare curves

15. 60

16. Stress, Emergency (fight or flight) Effect on Beta cells Effect on Alpha Cells