Jeef First Aid Renal Part 1-3

Front 1

46. Action of PTH?

Back 1

a. Inhibits Na+/phosphate cotransport-> Phosphate excretion.

Front 2

47. Action of Angiotensin II in Proximal tubule?

Back 2

a. Stimulates Na/H+ exchange -> ↑ Na+ and H20 reabsorption (permitting contraction alkalosis).

Front 3

48. Action of thick ascending LOH?

Back 3

a. Actively reabsorbs Na, K, and Cl.
b. Indirectly induces the paracellular reabsorption of Mg2+ and Ca2+.
c. Impermeable to H20!
d. Makes urine LESS concentrated.

Front 4

49. Action of Early distal tubule?

Back 4

a. Actively reabsorbs Na and Cl-.
b. Diluting segment- Makes urine hypotonic.

Front 5

50. Where does PTH act and what is its action?

Back 5

a. Early DCT.
b. ↑ Ca/Na exchange -> Ca2+ reabsorption.

Front 6

51. Action of collecting tubules?

Back 6

a. Reabsorb Na in exchange for secreting K and H (regulated by aldosterone).

Front 7

52. How does aldosterone cause reabsorption of Na in collecting tubules?

Back 7

a. Aldosterone leads to insertion of (reabsorbing) Na channel on luminal side.

Front 8

53. Where does ADH act in the kidney and what is its action?

Back 8

a. Acts at V2 receptors in collecting tubules.
b. Causes insertion of Aquaporin H2O channels on luminal side.

Front 9

54. TF/P > 1 when? (TF/P = Tubular fluid/plasma)

Back 9

a. Solute is reabsorbed less quickly than water
b. There is net secretion of solute.

Front 10

55. TF/P = 1 when? (TF/P = Tubular fluid/plasma)

Back 10

a. Solute and water are reabsorbed at same rate

Front 11

46. Action of PTH?

Back 11

a. Inhibits Na+/phosphate cotransport-> Phosphate excretion.

Front 12

47. Action of Angiotensin II in Proximal tubule?

Back 12

a. Stimulates Na/H+ exchange -> ↑ Na+ and H20 reabsorption (permitting contraction alkalosis).

Front 13

48. Action of thick ascending LOH?

Back 13

a. Actively reabsorbs Na, K, and Cl.
b. Indirectly induces the paracellular reabsorption of Mg2+ and Ca2+.
c. Impermeable to H20!
d. Makes urine LESS concentrated.

Front 14

49. Action of Early distal tubule?

Back 14

a. Actively reabsorbs Na and Cl-.
b. Diluting segment- Makes urine hypotonic.

Front 15

50. Where does PTH act and what is its action?

Back 15

a. Early DCT.
b. ↑ Ca/Na exchange -> Ca2+ reabsorption.

Front 16

51. Action of collecting tubules?

Back 16

a. Reabsorb Na in exchange for secreting K and H (regulated by aldosterone).

Front 17

52. How does aldosterone cause reabsorption of Na in collecting tubules?

Back 17

a. Aldosterone leads to insertion of (reabsorbing) Na channel on luminal side.

Front 18

53. Where does ADH act in the kidney and what is its action?

Back 18

a. Acts at V2 receptors in collecting tubules.
b. Causes insertion of Aquaporin H2O channels on luminal side.

Front 19

54. TF/P > 1 when? (TF/P = Tubular fluid/plasma)

Back 19

a. Solute is reabsorbed less quickly than water
b. There is net secretion of solute.

Front 20

55. TF/P = 1 when? (TF/P = Tubular fluid/plasma)

Back 20

a. Solute and water are reabsorbed at same rate

Front 21

56. TF/P < 1 when? (TF/P = Tubular fluid/plasma)

Back 21

a. Solute is reabsorbed more quickly than water.

Front 22

57. Where do Tubular creatinine and inulin ↑ in concentration (but not amount)?

Back 22

a. Along the proximal tubule due to water reabsorption.

Front 23

58. How does Cl reabsorption compare to Na reabsorption in the proximal tubule and more distally?

Back 23

a. Cl reabsorption occurs at a slower rate than Na in the proximal 1/3 of the proximal tubule and then matches the rate of Na reabsorption more distally.
b. Thus, its relative concentration ↑ before its plateaus

Front 24

59. Na vs. H20 reabsorption?

Back 24

a. Na reabsorption drives H2O reabsorption, so it nearly matches osm.

Front 25

60. Action of AT II in renin-angiotensin-aldosterone system?

Back 25

a. Affects baroceptor function.
b. Limits reflex bradycardia, which would normally accompany its pressor effects.

Front 26

61. 6 Actions of Angiotensin II?

Back 26

1. Acts at AT II receptors on vascular smooth muscle-> vasoconstriction- ↑ BP.
2. Constricts EFFERENT arteriole -> ↑ FF to preserve renal function (GFR) in low-volume states (i.e., when RBF ↓).
3. Aldosterone
4. Stimulates ADH (posterior pituitary) ↑H2O channel insertion in principal cells -> H20 reabsorption.
5. ↑ proximal tubule Na/H activity -> H20 reabsorption.
6. Stimulates hypothalamus -> Thirst.

Front 27

62. Action of ANP in renin-angiotensin-aldosterone system?

Back 27

a. Released from atria in response to ↑ volume.
b. May act as a “check on renin-angiotensin-aldosterone.
c. Relaxes vascular smooth muscle via cGMP, causing ↑ GFR, ↓ renin.

Front 28

63. Action of ADH in renin-angiotensin-aldosterone system?

Back 28

a. Primarily regulates osmolarity but also responds to low blood volume, which takes precedence over osmolarity.

Front 29

64. Action of aldosterone in renin-angiotensin-aldosterone system?

Back 29

a. Primarily regulates blood volume.
b. In low-volume states, both ADH and aldosterone act to protect blood volume.
c. ↑ Na channel, Na/K pump insertion in principle cells.
d. Enhances K+ and H+ excretion (up-regulates principle cell K channels and intercalated cell H+ channels).
e. All of this creates favourable Na gradient for Na and h20 reabsorption.

Front 30

65. What are JG cells and where are they?

Back 30

a. Modified smooth muscle cells of the AFFERENT ARTERIOLE.
b. JG cells secrete renin in response to ↓ BP, ↓ Na delivery to distal tubule, and ↑ sympathetic tone (β1).

Front 31

66. What are macula densa cells and where are they?

Back 31

a. Na+ sensor, part of the DCT.

Front 32

67. 4 kidney endocrine functions?

Back 32

1. Erythropoietin (you are calling it epo for short)
2. 1,25-(OH)2 vitamin D.
3. Renin
4. Prostaglandin.

Front 33

68. When is epo released and from what cells?

Back 33

a. In response to hypoxia from endothelial cells of peritubular capillaries.

Front 34

69. Where in the kidney is 25-Vit D converted to 1,25?

Back 34

a. Proximal tubule cells convert it.

Front 35

70. Action of vit D?

Back 35

a. ↑ intestinal reabsorption of both calcium and phosphate.

Front 36

71. Action of PTH?

Back 36

a. PTH acts directly on kidney to ↑ renal calcium reabsorption and ↓ renal phosphate reabsorption.
b. However, PTH also acts indirectly, stimulates proximal tubule cells to make 1,25-D, which ↑ intestinal absorption of BOTH calcium and phosphate.

Front 37

72. How can NSAIDS cause acute renal failure?

Back 37

a. By inhibiting the renal production of prostaglandins, which keep the afferent arterioles vasodilated to maintain GFR.

Front 38

73. What is Renin secreted by and what is its effect?

Back 38

a. JG cells in response to ↓ renal arterial pressure and ↑ renal sympathetic discharge (β1 effect).

Front 39

74. Prostaglandins in kidney (e.g., PGE2)- From where are they secreted and what is their effect?

Back 39

a. Paracrine secretion vasodilates the afferent arterioles to ↑ GFR.

Front 40

75. Action of Atrial Natriuretic peptide on kidney?

Back 40

a. Secreted in response to ↑ atrial pressure.
b. Causes ↑ GFR and ↑ Na filtration WITH NO COMPENSATORY Na REABSORPTION IN DISTAL NEPHRON
c. Net effect: Na loss and volume loss.