A&P URINARY SYSTEM

1. A&PURINARYSYSTEM Instructor Terry Wiseth

2. Urinary Anatomy • Kidney • Ureter • Bladder • Urethra

3. Functions of Urinary System • Clears blood of waste products of metabolism • Uremia • accumulation of toxic levels of wastes in blood • maintain normal • H2O and electrolyte balance • fluid volumes • blood pressure • body pH

4. Kidneys • Excretory Organ • Intestine, Skin, Lungs • Excretes • N2 wastes • Toxins • H20 • Electrolytes

5. Microscopic Structure • Nephron • unit of function • 1.25 million / kidney • Highly vascular • 20% of blood pumped / min

6. Functions • 1) maintain fluid balance • 2) maintain electrolyte balance • 3) maintain acid-base balance • 4) remove N2 wastes • urea • 5) synthesize prostaglandin's • 6) influence rate of secretion of hormones • ADH / Aldosterone

7. Kidney Failure • blood constituents cannot be held in normal concentrations

8. Nephron Anatomy • 1) Glomerulus • Arterioles • Bowman’s Capsule • 2) Tubule • Proximal • Loop of Henle • Ascending • Descending • Distal • Collecting

9. Urine Formation • Actions in forming urine • 1) filtration • 2) reabsorption • 3) secretion

10. Glomerular Filtration • blood flows through glomerular capillaries • H2O and solutes filter out into Bowman’s Capsule

11. Glomerular Filtration • blood flows through glomerular capillaries • H2O and solutes filter out into Bowman’s Capsule

12. Glomerular Filtration • pressure gradient causes filtration • some kidney diseases • permeability of glomerulus increases • allows blood proteins to filter out into the capsule

13. Glomerular Filtration • High blood pressure in the glomerulus forces small molecules from blood into the Bowman’s capsule

14. Glomerular Filtration • TEM of filtration slits from capillaries in Bowman’s Capsule

15. Glomerular Filtration • Stress can lead to constriction of afferent arterioles • causes filtration rate to lower • and renal suppression “kidney shutdown”

16. Glomerular Filtration • glomerular filtration ratedirectly related to systemicblood pressure • ↓ BP = ↓ glomerular filtration • ↑ BP = ↑ glomerular filtration (slight)

17. Tubular Reabsorption • movement of substances from tubular fluid out to blood • reabsorption from proximal convoluted tubules to blood

18. Tubular Reabsorption • movement of substances from tubular fluid out to blood • reabsorption from proximal convoluted tubules to blood

19. Tubular Reabsorption • Glucose, amino acids, ions and other useful substances are actively transported from the tubule into blood

20. Proximal Tubules • Water follows passively by osmosis

21. Glucose Reabsorption • if blood glucose levels exceed threshold amount (150mg/100ml) • not all glucose is reabsorbed

22. Renal Diabetes • congenital • sometimes maximum transfer capacity is reduced and excess glucose appears in urine even though blood glucose level is normal

23. Reabsorption from Loop of Henle • Descending Loop • Water diffuses out of the tubule by osmosis

24. Reabsorption from Loop of Henle • Ascending Loop • Salts are actively transported out of the tubule, but water cannot follow because the walls of the tubule are impermeable to water

25. Reabsorption from Loop of Henle • NaCl is trapped in interstitial fluid of kidney medulla

26. Reabsorption from Distal Tubules • proximal tubules reabsorb 2/3 of Na+ • distal tubules reabsorb 1/10 of Na+

27. Reabsorption from Distal Tubules • distal tubules reabsorb H2O if antidiuretic hormone (ADH) is present

28. Distal Tubule • K+, H+ and other ions, and certain large molecules are actively transported from the blood into the tubule, regulating the pH and ionic concentration of the blood

29. Collecting Duct • As the urine passes down the duct, water moves by osmosis from the duct into the blood

30. Collecting Duct • As the urine passes down the duct, water moves by osmosis from the duct into the blood

31. ADH • cause distal tubules to become permeable to H2O

32. ADH • small concentrated volume of urine is excreted

33. ADH • if no ADH in blood, then large volumes of urine produced (dilute concentration)

34. Regulation of Urine Volume • 1) ADH • 2) Aldosterone • 3) Extracellular fluid volume • 4) Urine solute concentration

35. Regulation of Urine Volume • 1) ADH • Presence • decrease Urine Volume • Absence • increase Urine Volume

36. Regulation of Urine Volume • 2) Aldosterone • increases Na+ reabsorption in distal tubule with H2O following

37. Regulation of Urine Volume • 3) urine volume relates directly to extracellular fluid volume (ECF) • ECF ↓ urine volume ↓ • ECF ↑ urine volume ↑ • rapid ingestion of largeamount of fluid and resultingincreased ECF leads toincreased urinary output

38. Regulation of Urine Volume • 4) high solute concentration in urine increases urine volume by osmotic pressure • untreated diabetes • void large amounts of urine because excess glucose in blood “spilling over”

39. Influence of Kidney on Blood Pressure • Renal Hypertension • decreased blood flow to kidney • constriction of arterioles • increased BP

40. Ureters • Tubes leading from kidney to bladder • Urine moves by peristaltic movement

41. Ureters • Renal Calculi • stones develop in kidney, washed out by urine into ureter • distend ureter walls • pain

42. Bladder • collapsible, elastic bag • Ureters • 2 • Bladder • Urethra • 1

43. Functions of Bladder • 1) reservoir for urine • 2) expels urine • distended causes sensation and desire to void

44. Urethra • passageway for eliminating urine

45. Urethra • passageway for eliminating urine

46. Urine • H2O • 95% • N2 wastes • Electrolytes • Toxins • Pigments • Hormones

47. Artificial Kidney • Dialysis

48. Artificial Kidney • Dialysis

49. Artificial Kidney • continuous ambulatory peritoneal dialysis (CAPD) • dialysis fluid administered to peritoneal cavity

50. Kidney Transplant