Glomerular Filtration Physiology

  1. Where does the glomerulus chill in?
    Bowman’s capsule
  2. Where does the filtrate go to right after exiting bowman’s capsule?
    Proximal tubule
  3. True/False: the descending loop of henle is thick while the ascending limb is thin
    False; descending loop is thin, and ascending limb is thick
  4. The _____ tubule gets in close proximity to the bowman’s capsule and contains macula densa cells.
    Distal convoluted
  5. What are the three layers of the filtration barrier of the capillary endothelium?
    • First layer: fenestrated capillary endothelium
    • Second layer: basement membrane
    • Third layer: podocytes
  6. What is the function of mesangial cells?
    Sits in the junction of afferent and efferent arterioles and remove trash
  7. What’s not filtered?
    • Blood cells
    • Plasma proteins
    • Large anions
    • Protein-bound minerals and hormones
    • Large molecules greater than 8 nm
  8. What gets passed through the filter into the bowmans capsule?
    • Water
    • Electrolytes
    • Glucose
    • Amino acids
    • Fatty acids
    • Vitamins
    • Urea
    • Uric acid
    • Creatinine
  9. True/false: glucose is passed through the filter into bowmans capsule
  10. True/false: plasma proteins get filtered
    False; proteins don’t, amino acids do
  11. True/false: vitamins and fatty acids get filtered
  12. True/false: large anions get filtered
  13. True/false: electrolytes get filtered
  14. True/false: creatinine, urea and uric acid get filtered
  15. True/false: carbon nanotubes can serve as drug delivery vehicles and clears renal filtration despite its large size
  16. How many liters of glomerular filtrates does the kidney produce in a day? How many becomes urine?
    • 180 L (male) 150 L (female)
    • 1-2L urine
  17. What is normal GFR per minute?
    125 mL/min
  18. How is glomerular filtrates of 180 L calculated?
    GFR of (125 mL/min) x (60 min/hr) x (24 hours/day) = 180, 000 mL/day = 180 L/day
  19. What is the renal blood flow in a minute?
    1100 mL/min
  20. What is the renal plasma flow in a minute?
    524 ml/min
  21. What is normal urine flow per minute?
    1 mL/min
  22. What is filtration fraction?
    • Fraction of plasma flow that becomes filtered
    • Percentage of filtered substance from arterioles
  23. How is filtration fraction calculated?
    FF= GFR / renal plasma flow
  24. What is the definition of glomerular filtration rate?
    The quantity of glomerular filtrate formed in ALL nephrons of both kidneys PER MINUTE
  25. What is the filtration coefficient (Kf)?
    The GFR for both kidneys per mmHG of filtration pressure
  26. What is the normal filtration coefficient (Kf)?
  27. GFR is typically calculated under how many filtration pressure?
    10 mmHg
  28. What is the capillary blood pressure?
    • Pressure going out from the blood vessel into the bowmans capsule
    • 60 mmHg (going out of the capillary into bowmans capsule)
  29. What is the colloid osmotic pressure?
    • Pressure that is coming out of the bowman’s capsule into the capillary
    • 32 mmHg (going into the capillary)
  30. What is the net filtration pressure?
    10 mmHg into the Bowman’s capsule
  31. What is oncotic pressure for bowman’s capsule?
    0 because there is no protein in the bowman’s capsule
  32. What is the capsular pressure?
    • Pressure exerted from the bowman’s capsule onto the capillary
    • 10 mmHg (going into the capillary)
  33. How is the net filtration pressure calculated?
    • Capillary blood pressure – colloid osmotic pressure – capsular pressure= net
    • (60mmHg– 32 mmHg – 18 mmHg = 10 mmHg)
  34. True/false: protein concentration is higher on afferent arteriole
    False; protein is higher on efferent side because proteins do not get filtered out of blood while electrolytes and water do, therefore making the efferent side more concentrated
  35. Oncotic pressure is higher on _____ arteriole, and therefore will ____ fluid to/from bowman’s capsule
    • Efferent
    • Pull
    • From
  36. What is the relationship between renal blood flow/GFR and resistance?
    when resistance increase, renal blood flow and GFR decreases
  37. What is the relationship between renal blood flow/GFR and resistance?
    • Any resistance would decrease renal blood flow
    • At 2x the resistance, GFR would increase, however at 3x resistance or above, GFR would subsequently drop
  38. What is the Donnan effect?
    at greater than 3x the resistance in efferent arteriole, the GFR would go down
  39. Afferent arteriole dilation would ______ GFR
  40. Efferent arteriole dilation would ____ GFR
  41. What are substances that constrict Afferent arteriole?
    Sympathetic stuff ie Adrenaline, Norepinephrine, endothelin
  42. What are substances that lead to afferent arteriole dilation?
    Prostaglandin, E2, NO2, bradykinin
  43. What is the effect of angiotensin II on efferent arterioles?
    Constriction of efferent arteriole
  44. Afferent and efferent constriction would ______ renal blood flow
  45. Afferent and efferent dilation would _____ renal blood flow
  46. Afferent constriction would ______ glomerular capillary pressure and GFR
  47. Afferent dilation would _____ glomerular capillary pressure and GFR
  48. Efferent constriction would _____ glomerular capillary pressure and GFR
  49. Efferent dilation would ______ glomerular capillary pressure and GFR
  50. Peritubular capillary pressure would ____ with vessel dilation
  51. peritubular capillary pressure would ____ with vessel constriction
  52. Peritubular capillary reabsorption would ___ with vessel dilation
  53. Peritubular capillary reabsorption would ____ with vessel constriction
  54. What is myogenic mechanism?
    A theory of autoregulation of renal blood flow and GFR that smooth muscle cells have inherent tendency to contract when stretched ie during high arterial pressure
  55. What is tubuloglomerular feedback?
    A theory of autoregulation of renal blood flow and GFR that macula densa cells in the distal convoluted tubule detect NaCl level and increase GFR if low NaCl detected
  56. What is macula densa cell?
    Osmotic sensor for salt, affect afferent arteriole resistance
  57. True/False: macula densa affects efferent arteriole resistance
    False; they affect afferent arteriole resistance
  58. True/false: juxtaglomeruluar cells respond to decrease in afferent arteriole pressure by vasoconstriction and by release renin
  59. Which cell produces renin?
    Juxtaglomerular cells
  60. What happens to GFR if there is decrease NaCl?
  61. What happens to GFR if afferent arteriole resistance decreases?
    Increase GFR
  62. What are juxtaglomerular cells?
    Detect blood pressure
  63. What happens to GFR when there is increased renin release?
    Increase GFR
  64. What is the mechanism in which renin affect GFR?
    Renin released -> increase angiotensin II production -> increase constrictions efferent arteriole -> increase in glomerular hydrostatic pressure -> GFR increase
  65. True/false: diabetes can decrease GFR
  66. True/false: hypertension can decrease GFR
  67. What are factors that can increase GFR?
    • Hypoalbuminemia
    • Increased nitric oxide vasodilator
    • Increase prostaglandin vasodilator
  68. Atrial natriuretic peptide (ANP) ____ (increases/decreases) GFR
  69. True/False: GFR increases in response to ANP to reduce blood volume
  70. ANP levels are elevated during which states?
    Hypervolemic states (ie elevated blood volume, heart failure)
  71. How do Hematuria and proteinuria usually occur?
    When there is damage to the filtration barrier i.e. to the endothelial cell, basement membrane or the podocytes which allows blood to leak through
Card Set
Glomerular Filtration Physiology
Renal Midterm- Physiology