C8 FORMATION OF URINE BY THE KIDNEY

1. C8 FORMATION OF URINE BYTHE KIDNEY

2. Today I am going to introduce: 1.the microstructure of the Kidney 2. glomerular filtration

3. our goals are ⑴ understand microstructure of the kidney ⑵ understand the characteristic of blood circulation in the kidney ⑶ describe glomerular filtration

5. Functions of The kidney: ⑴ regulate water and inorganic ion equilibrium .maintain constant of internal environment regulate the osmotic pressure of body fluids; • the osmotic pressure is formed by electrolyte, kidney regulate value of electrolyte , acid and baseexcretion, and then regulate the osmotic pressure , the electrolyte equilibrium and adjust the balance of acid and base in body fluids.

6. ⑵ excrete metabolic waste end-products into the urine; • NH3 some poisons

7. ⑶ excrete foreign chemicals drugs metabolites ⑷gluconeogenesis synthesize glucose from amino acids . ⑸endocrine function secreteerythropoietin, renin,

8. Which is main function of the kidney? excrete urine produce urine Store urine Transport urine

9. Which is main function of the ureter ? excrete urine produce urine Store urine Transport urine

10. Mechanisms of urine formation : (1) Filtration (2) Secretion (3) Reabsorption

12. Structure of the kidneys and urinary system

13. cortex medulla

14. The Nephron and collecting Duct 2,000,000 nephrons Functional unit of kidney

15. ① composition of nephron glomerulus renal corpuscle Bowman’s capsule nephron proximal convoluted tubule renal tubule loop of Henle; distal convoluted tubule The collecting duct

18. What is functional unit of the kidney? nephron glomerulus renal tubule collecting duct

19. ② types of nephron (1)cortical nephrons:(85% ) In the outer and middle portion of the renal cortex (shorter loops)

20. cortical nephrons juxtamedullary nephrons loop of Henle Collecting duct

21. ② types of nephron (2) juxtamedullary nephrons : (15% ) In the inner cortex (longer loops)

22. cortical nephrons juxtamedullary nephrons loop of Henle Collecting duct

23. Juxtaglomerular Apparatus (1)the juxtaglomerular cells: they are specialized myoepithelial cells in afferent arteriole release renin

24. monitor the concentration of NaCl in the tubular fluid and transferthe information to juxtaglomerular cells (2)the macula densa :

25. What is cell of release renin? extraglomerular mesangial cell juxtaglomerular cells macula densa

26. What is cell ofmonitor the concentration of NaCl in the tubular fluid? juxtaglomerular cells extraglomerular mesangial cell macula densa

27. Glomerular Membrane physical barrier 1.The endothelial layer of the capillary 2.The basement membrane 3.The epithelial cell layer of Bowman’s capsule

28. special structure Fenestra: prevent the filtration of all particles with an average size greater than 16 millimicron. Red cell

29. Meshwork(basement membrane of the capillary) proteoglycan prevents the filtration of all particles with diameter greater than 11 millimicron

30. Slit-pores

31. Slit-pores prevent the filtration of all particles with diameter greater than 7 millimicron. (diameter of plasma proteins ﹥7 millimicron) plasma proteins

32. Electrical barrier - - - - - - - - Glycoprotein (negatvely charge)

33. - - - - - - - - prevent filtration of negatively charged plasma proteins

34. Neutral substances: ﹤2 nm(millimicron) –can be filtered easily ﹥4.2 nm--can not be filtered between---can be filtered proportionately Anionic substances: difficult to be filtered (albumin)

35. The glomerular membrane is almost completely impermeable to all cells and plasma proteins but is highly permeable to all dissolved substances(such as electrolyte, glucose )

37. In following substance , What substance is not filter through the glomerular membrane. plasma protein water ions electrolyte glucose

38. Innervation of the renal vessels Sympathetic fiber Sympathetic nerve cause constriction of renal blood vessels, which greatly decreases blood flow to the kidney.

39. Renal Blood Flow and Regulation renal artery → afferent arteriole→ glomerular capillaries →efferent arteriole→ peritubular capillaries → renal vein

40. Two capillary beds (1)glomerular capillary bed : high pressure →filtering continually out of the glomerulus into Bowman’s capsule

41. (2)peritubular capillary bed : low pressure → fluid being reabsorbed continually into the capillaries

42. What is characteristic of theglomerular capillary bed? low pressure high pressure

43. What is characteristic of theperitubular capillary bed? low pressure high pressure

44. (1)Renal Blood Flow ① renal blood flow is about 1200ml/minute ② The renal fraction is about 21 per cent

45. ③ About 94 per cent of renal blood flow goes to the renal cortex.

46. (2) Autoregulation of Renal Blood Flow When BP changes from 80 to 180 mmHg, a relatively constant renal blood flow is maintained.

47. mechanism * When BP descends, afferent arteriole relax and decrease resistance of afferent arteriole, and then the renal blood flow does not change. * When BP rises, afferent arteriole contract and increase resistance of afferent arteriole, and then the renal blood flow does not change, too

48. (3)Neuro-Humoral Control Sympathetic nerve: → constriction of renal blood vessels →decreases blood flow Vasoconstrictor agents : Angiotensin II epinephrine and norepinephrine Vasodilator agents : bradykinin, NO and some prostaglandins

49. plasma → Bowman’s capsule→ proximal convoluted tubule → loop of Henle → distal convoluted tubule→ collecting duct → papilla → renal alyces

50. Glomerular Filtration when blood passes through the glomerulus, plasma component (water, ions, and small molecules filter into Bowman's capsule.