1. RENAL PHYSIOLOGY TUTORIAL-2 DISCUSSION Dr. Zahoor 1

2. TOPICS Counter Current Mechanism Acid Base Balance 2

3. Q1. What does word ‘Counter Current’ means? 3

4. Q2. Name the four mechanisms which help in counter current mechanism (concentration mechanism of urine). 4

5. Q3. How loop of Henle (counter current multiplier) establishes the concentration gradient in the renal medulla? 5

6. Q4. What is the role of Vasarecta (counter current exchanger) in the counter current mechanism? 6

7. Q5. Why medullary interstial Osmolarity is important for concentration of urine? 7

8. Q6. If there is no medullary concentration, what will happen? 8

9. Q7. What is the Osmolarity of interstial fluid in the medullary interstium? 9

10. Q8. What is the role of ADH in the concentration mechanism of urine? 10

11. Q9. Where does the ADH act on DCT and CT? 11

12. Q10. How much water is reabsorbed in the DCT and CT under the action of ADH? 12

13. Q11. If ADH is not there, urine will be concentrated or dilute? 13

14. Q12. If a person is fasting and has taken no water for 10 hours, why he passes less amount of concentrated urine? 14

15. Q13. If a person drinks 1 liter of water, why he passes more amount of dilute urine? 15

16. Q14. What is role of urea in the concentration mechanism of urine? 16

17. Q15. What is urea cycle in the counter current mechanism? 17

18. Q16. What is Micturition or urination reflex? 18

19. Q17. Where is the center for Micturition reflex? 19

20. Q18. Urinary bladder smooth muscle contraction is function of (select one) 1. Sympathetic ANS 2. Parasympathetic ANS 20

21. Q19. What is the capacity of normal urinary bladder in the adult person? 21

22. Q20. As urine is collected in the urinary bladder, when initial urge is felt for urination? 22

23. Q21. Urination is under voluntary control, how? 23

24. Q22. What is pH? 24

25. Q23. What is pH of water? 25

26. Q24. What is pH of blood? 26

27. Q25. In the human, what pH is compatible with life? 27

28. Q26. If pH or arterial blood is 7.3, is it normal or abnormal? 28

29. Q27. If H+ ion increases, pH will be: Select one 1. Acidic 2. Alkaline 29

30. Q28. What is normal pH of urine? 30

31. Q29. What could be the lowest pH of urine? 31

32. Q30. Why pH of blood, if acidic or alkaline is dangerous for the body? 32

33. Q31. How body regulates the pH. Give three defense mechanism. 33

34. Q32. What are body chemical buffers which operate in seconds? 34

35. Q33. How respiration regulates the acid base balance? 35

36. Q34. What is the role of kidney in acid base balance? 36

37. Q35. How kidney secretes H+ ion? Draw diagram. 37

38. Q36. Where H+ ion is secreted in the tubule? 38

39. Q37. How new HCO 3 - ion is generated and reabsorbed? 39

40. Q38. Name the kidney buffers? 40

41. Q39. If there is metabolic alkalosis, what does the kidney do? 41

42. Q40. In Respiratory acidosis/alkalosis, what will happen to Resp. acidosis Resp. alkalosis pH CO 2 HCO 3 42

43. Q41. In metabolic acidosis/alkalosis, what will happen to Meta. acidosis Meta. alkalosis pH CO 2 HCO 3 43

44. Q42. If a person has vomiting, his blood pH is found to be 7.5 CO2 38mmHg, HCO3 34meq/l. What type of acid base disorder he is having? 44

45. THANK YOU 45