1. Biology 305 Lab Last Lab Lecture

2. ANNOUNCEMENTS Final Exam is Fri. May 5 th (NEXT Fri!) LH7 Noon – 2 pm NO MAKEUPS My Office Hours next week: Wednesday May 3 rd from 2 – 4pm Thursday May 4 th from 1 – 3pm

3. ANNOUNCEMENTS Final Exam: –Exam is non-cumulative! –Be SPECIFIC in your answers! –Format: –Multiple choice –Fill in the blank –True/False –Short answer questions –Essays –Will post practice final by COB

4. ANNOUNCEMENTS Final Exam viewing (wake) Time/day TBA Check web site for announcement –Other graded assignments (lab Reports, quizzes & lab notebook) will be handed back during exam “wake”

5. HUMAN RENAL PHYSIOLOGY Regulation of Body Fluid Volume: –Kidneys influence fluid volume by: –Altering water content of urine

6. HUMAN RENAL PHYSIOLOGY Retention of Water is controlled by ADH: –Anti Diuretic Hormone –ADH Release Is Controlled By: –Increase in ECF Osmolarity (mainly) –Decrease in Blood Volume –Decrease in Blood Pressure

7. HOMEOSTATIC MECHANISM FOR WATER BALANCE IS MEDIATED BY ADH HUMAN RENAL PHYSIOLOGY

8. HUMAN RENAL PHYSIOLOGY Sodium Balance Is Controlled By Aldosterone –Aldosterone: Steroid hormone Synthesized in Adrenal Cortex Causes reabsorbtion of Na+ in DCT & CD –Also, K+ secretion

9. HUMAN RENAL PHYSIOLOGY Sodium Balance Is Controlled By Aldosterone: –Aldosterone Release: Triggered by increased ECF K+  Na+ reabsorbtion –Inhibition of Aldosterone: Triggered by increased extracellular osmolarity  No Na+ reabsorbtion

10. HUMAN RENAL PHYSIOLOGY Maintain fluid volume but increase osmolarity: Eating salty food (chips) without fluid intake –ADH plays significant role in urine concentration –Highly concentrated urine of low volume

11. HUMAN RENAL PHYSIOLOGY Increase fluid volume and decrease osmolarity: –Drink pure (distilled) water Copious amounts of dilute urine »No ADH

12. What about presence of glucose and/or caffeine? Coke: –Glucose (+ similar sugar) is reabsorbed in nephron –Caffeine opposes action of ADH Removal of H 2 O in urine = diuresis –Dilute urine produced HUMAN RENAL PHYSIOLOGY

13. What about presence of artificial sweeteners? Diet coke –Artificial sweeteners tend to be secreted and excreted More concentrated urine produced (esp. if no caffeine is present)

14. HUMAN RENAL PHYSIOLOGY Results from lab