Firecracker

Question 1

What is acetazolamide?

Answer 1

Carbonic anhydrase inhibitors act in the PCT by inhibiting the reabsorption of filtered HCO3-.

Question 2

Uses of acetazolamide?

Answer 2

• weak diuretic
• To alkalinize the urine
• To treat glaucoma
• To treat metabolic alkalosis
• To treat altitude sickness

Question 3

how does acetazolamide treat glaucoma?

Answer 3

(↓ secretion of aqueous humor → ↓ intraocular pressure)

Question 4

acetazolamide toxicity

Answer 4

• Hyperchloremic metabolic acidosis
• Hypokalemia
• NH3 toxicity
• Neuropathy
• Sulfa allergy

Question 5

Effect of ↓FF on protein concentration in peritubular capillary blood?

Answer 5

↓ and decreased reabsorption in the proximal tubule

Question 6

How are Mg and Ca absorbed in the thick ascending loop of Henle?

Answer 6

K leak channels in the luminal membrane allow electrochemical potential gradient to drive further reabsorption of cations: K, Mg+ and Ca+

Question 7

OPgc decreases by decreases in capillary protein concentration, such as in cirrhosis or nephrotic syndrome –> increased GFR.

Answer 7

increased GFR.

Question 8

What effect does the thick ascending loop of Henle have on the tonicity of urine?

Answer 8

dilutes

Question 9

Effect of ↑FF on protein concentration in peritubular capillary blood?

Answer 9

↑ –> increased reabsorption in the proximal tubule

Question 10

If C(x) < GFR, then there is a net tubular

Answer 10

reabsorption of X (example: Na, glucose, amino acids, HCO3-, Cl-)

Question 11

In the PCT (proximal convoluted tubule), name 3 buffer systems which serve to buffer urinary H+.

Answer 11

HCO3-
HPO32-
NH3

Question 12

What is the most important urinary buffer system in the PCT?

Answer 12

HCO3-

Question 13

Describe how ACE-Inhibitors can ↓GFR?

Answer 13

Angiotensin II preferentially constricts the efferent aterioles. ACE inhibitors thus dilate efferent arterioles –> ↓ GFR.

Question 14

MOA thiazide diureteics

Answer 14

inhibit Na/Cl cotransporter in DCT

Question 15

Thiazides are used to treat 4 things:

Answer 15

1. HTN
2. CHF
3. Idiopathic hypercalciuria
4. Nephrogenic DI

Question 16

Why use thiazides for nephrogenic DI?

Answer 16

Thiazides increase renal Na excretion → ECF volume contraction → ↓ GFR → ↑ proximal tubular reabsorption of water and Na
∴ less water and Na are lost as urine

Question 17

thiazide toxicity –> ↓ serum levels of 3 things:

Answer 17

sodium, potassium, H+
K (hypokalemia)
Na (hyponatremia)
H+ (metabolic alkalosis, ↑ HCO3-)

Question 18

thiazide toxicity –> ↑ serum levels of (mnemonic “GLUC”)

Answer 18

Glucose, lipids, uric acid, Ca2+

• Glucose (hyperglycemia)
• Lipids (hyperlipidemia)
• Uric acid (hyperuricemia) → may precipitate gout
• Ca2+ (hypercalcemia)

Question 19

Both thiazide diuretics and loop diuretics can cause

Answer 19

hypokalemia

Question 20

thiazide vs. loop effect on calcium

Answer 20

• thiazides increase Ca reabsorption
  ∴ thiazide toxicity may cause hypercalcemia
• loops increase Ca excretion
  ∴ loop diuretic toxicity may cause hypocalcemia.

Question 21

What regulates glucose in the PCT?

Answer 21

limited number of Na-glucose carriers

Question 22

How does aldosterone affect electrolyte balance in the kidney’s principal cells?

Answer 22

↑ Na reabsorption and ↑ K secretion

Question 23

cotrasnporter in the TAL of henle

Answer 23

NKCC symporter

Question 24

NKCC actively reabsobds

Answer 24

Active reabsorption of Na, K (or NH4+), and Cl-

Question 25

What competes with K for reabsorption by NKCC?

Answer 25

NH4

Question 26

fxn of intercalated cells in collecting tubule

Answer 26

secrete H & reabsorbs K

Question 27

How do the intercalated cells secrete H into the collecting tubule lumen?

Answer 27

primary active H-ATPase | primary active H-K-ATPase

Question 28

How do the intercalated cells reabsorb K from and secrete H into the collecting tubule lumen?

Answer 28

Primary H-K-ATPase

Question 29

Aldosterone effect on intercalated cells, aldosterone further increases H secretion by

Answer 29

intercalated cells

Question 30

Under conditions of K depletion, K reabsorption by Type A intercalated cells predominates over what to → net K reabsorption.

Answer 30

K secretion by principal cells in the distal nephron

Question 31

When K intake is normal or high, K secretion by principal cells far outweighs what to→ net K secretion.

Answer 31

K reabsorption by Type A intercalated cells in the distal nephron

Question 32

In PCT, what pump maintains a gradient that favors passive Na reabsorption from the lumen into the renal tubular cells?

Answer 32

Na/K ATPase in the basolateral membrane extrudes Na from renal tubular cells into the interstitium

Question 33

Spironolactone and eplerenone are

Answer 33

competitive aldosterone receptor antagonists which act on the cortical collecting tubule.

Question 34

Where does spironolactone work?

Answer 34

cortical collecting tubules

Question 35

What drugs directly block epithelial sodium channels to inhibit sodium reabsorption in the collecting ducts without depleting potassium.

Answer 35

Amiloride and triamterene

Question 36

necessity of aldosterone for spironolactone?

Answer 36

imperative

Question 37

necessity of aldosterone for amiloride?

Answer 37

not necessary

Question 38

[Na+] – ([HCO3-] + [Cl-])

Answer 38

serum anion gap

Question 39

normal serum anione gap

Answer 39

8-16

Question 40

How is Na reabsorbed in the distal convoluted tubule?

Answer 40

Na-Cl cotransporter

Question 41

What artery supplies the bladder?

Answer 41

internal iliac artery.

Question 42

Is the urine osmolarity increased or decreased as it advances into the distal convoluted tubule?

Answer 42

decreased

Question 43

sympathetic relaxes or contracts bladder tone?

Answer 43

relaxes

Question 44

parasympathetic relaxes or contracts bladder tone

Answer 44

contracts (-->empties)

Question 45

In PCT, reabsorption of phosphate is directly linked to

Answer 45

NPT2, a sodium-phosphate cotransporter which serves as the primary functional regulator of phosphate reabsorption.

Question 46

PTH (parathyroid hormone) induces NPT2 endocytosis →

Answer 46

↓ reabsorption of phosphate and ↓ reabsorption of HCO3-

Question 47

sympathetic innervation of bladder

Answer 47

Preganglionic cell bodies located in the intermediolateral cell column --> inferior hypogastric plexus --> postganglionic cells project to the vesical plexus.

Question 48

histo DCT

Answer 48

simple cuboidal cells with NO brush border

Question 49

Mannitol works by osmotic diuresis in which part of the nephron?

Answer 49

PCT

Question 50

MOA loop diuretics

Answer 50

block the NKCC symporter in the TAL) of Henle’s loop

Question 51

loop diuretic examples

Answer 51

furosemide, bumetanide, ethacrynic acid

Question 52

site of action for K sparing diuretics

Answer 52

principal cells

Question 53

examples of K sparing diuretics

Answer 53

amiloride, triamterene, spirinolaction, eplerenone

Question 54

splay can be explained by

Answer 54

1) Nephron heterogeneity | 2) Relatively low affinity of Na-glucose cotransporters

Question 55

afferent arterioles contract in response to stretch caused by increased arterial pressure

Answer 55

Myogenic mechanisms of RBF autoregulation

Question 56

type 4 renal tubular necrosis (aldosterone deficiency or resistance):

Answer 56

hyperkalemia, urine pH<5.5.

Question 57

Principal cell function

Answer 57

secrete K+; reabsorb Na+ and H2O

Question 58

Principal cell function

Answer 58

secrete K+; reabsorb Na+ and H2O