Cardio V

Question 1

What is the most metabolically active part of the nephron? Second?

Answer 1

Proximal convoluted tubule

Thick ascending

Question 2

What is the order of the nephron? (7)

Answer 2

Proximal
Thick descending
Thin Descending
Think Ascending
Think ascending
Distal convoluted
Collecting duct

Question 3

Where is most of the Na/potassium in the renal tubule reabsorbed? Is this regulated?

Answer 3

Proximal convoluted tubule

Not regulated

Question 4

What is the primary process that is occurring in the thin descending loop of henle?

Answer 4

Water reabsorption passively

Question 5

What is the primary process that is occurring in the thick ascending loop of henle?

Answer 5

Reabsorption of electrolytes, no water

Question 6

What is the primary process that is occurring in the distal convoluted tubule?

Answer 6

Na Cl reabsorption–No K

Question 7

What is the primary process that is occurring in the collecting duct?

Answer 7

NaCl reabsorption

Question 8

Where does ADH work?

Answer 8

Collecting duct

Question 9

What part of the tubule is regulated for K uptake?

Answer 9

Distal convoluted tubule

Question 10

What are the processes that are occurring at the glomerulus?

Answer 10

Non

Question 11

Where is glucose reabsorbed in the nephron?

Answer 11

Proximal convoluted tubule

Question 12

What is the relative water permeability of the distal convoluted tubule?

Answer 12

Very low

Question 13

What is the primary transporter at the: glomerulus?

Answer 13

None

Question 14

What is the primary transporter at the: PCT?

Answer 14

Na/H exchanger

Carbonic anhydrase

Question 15

What is the primary transporter at the: Straight segments of the proximal tubule

Answer 15

Acid and base transporters

Question 16

What is the primary transporter at the: thin descending loop

Answer 16

aquaporins

Question 17

What is the primary transporter at the: thick ascending

Answer 17

Na/K/Cl

Question 18

What is the primary transporter at the: DCT

Answer 18

Na/Cl

Question 19

What is the primary transporter at the: cortical collecting tubule

Answer 19

Na channels
K channels
Aquaporins

Question 20

What is the primary transporter at the: medullary collecting duct

Answer 20

Aquaporins

Question 21

What happens when there is an increase in [Na] of the filtrate when it gets to the distal convoluted tubule?

Answer 21

Increased K excretion

Question 22

What is the prototypical carbonic anhydrase inhibitor?

Answer 22

Acetazolamide

Question 23

What is carbonic anhydrase needed for in the kidney? Where is it found?

Answer 23

HCO3 reabsorption in the proximal convoluted tubule

Question 24

What is the exchanger protein in the proximal convoluted tubule, that is responsible for the reuptake of Na? Which side of the tubular cell is this found on?

Answer 24

Na/H exchanger

Both lumenal and basolateral–pumps H+ from circulation all the way out to the tubule in exchange for Na

Question 25

What happens to the H+ that is secreted into the lumen of the renal tubule?

Answer 25

Combines with HCO3- to form bicarb

Question 26

What happens to the bicarbonate in the nephron lumen?

Answer 26

carbonic anhydrase converts it to CO2 and H2O. CO2 then goes back into the tubule cell, where it forms H2CO3 again in the cell

Question 27

Inhibition of carbonic anhydrase causes a major loss of what chemical in the urine? What chemical is maintained in the tubule? What is the effect of this on the circulation?

Answer 27

HCO3- lost NH4 maintained metabolic acidosis

Question 28

What happens when there is decreased HCO3 absorption by the PCT? What does this cause?

Answer 28

Increased solute delivery to the macula densa, increasing afferent arteriolar resistance, and decreasing renal blood flow

Question 29

What is tubular glomerular feedback?

Answer 29

Increased solute delivery to the macula densa leads to increased afferent arteriolar resistance, and low GFR

Question 30

What happens to Na/Cl when HCO3 flows out of the tubule?

Answer 30

Na and Cl follow

Question 31

Why is it that when carbonic anhydrase is inhibited, there is an increase in K excretion?

Answer 31

Loss of HCO3 increases Na/Cl excretion. Higher Na in the filtrate will increase K excretion

Question 32

Why are carbonic anhydrase inhibitors used in the treatment of glaucoma?

Answer 32

CA is present in the ciliary body, and plays a role in aqueous humor production

Question 33

What is the most common indication for carbonic anhydrase inhibitors?

Answer 33

glaucoma

Question 34

Why is carbonic anhydrase used in the treatment of acute mountain sickness?

Answer 34

CA is present in the choroid plexus. By decreasing CSF formation, and decreasing the pH of the CSF and brain, CA can increase ventilation and diminish symptoms of mountain sickness

Question 35

Why is carbonic anhydrase used in the treatment of gout or drug clearance?

Answer 35

Increased excretion of uric acid in alkaline urine caused by CA inhibitors

Question 36

Why is carbonic anhydrase used in the treatment of edema states?

Answer 36

Diuretic aspect

Question 37

Chronic reduction of HCO3 stores by CA inhibitors leads to what?

Answer 37

Hyperchloremic metabolic acidosis

Question 38

How does CA inhibitors lead to renal stones?

Answer 38

Increased excretion of Na leads to the build up of Ca salts

Question 39

How does renal K wasting occur with CA inhibitors? How can this effect be counteracted?

Answer 39

Increasing the lumen negative electrical potential in the collecting tubule enhances K excretion Administer KCl

Question 40

What diseases contraindicate CA inhibitors? Why?

Answer 40

Cirrhosis, hyperammonemia, and hepatic encephalopathy, because NH4 levels are increased with CA inhibitor

Question 41

What is the MOA of osmotic diuretics?

Answer 41

Osmotic agents that stay in the filtrate and cause water to be pulled into it

Question 42

What are the four osmotic diuretics?

Answer 42

Mannitol Glycerin Isosorbide Urea

Question 43

What is the main site of action of osmotic diuretics?

Answer 43

Thin loop of henle

Question 44

Why is there an increased loss of K with osmotic diuretics?

Answer 44

Increased distal flow in the distal tubule stimulates K secretion

Question 45

How do osmotic diuretics reduce acute tubular necrosis?

Answer 45

maintain flow through the tubule 2. Remove obstructing tubular casts 3. Dilution of nephrotoxic substances 4. Reduction of swelling of tubular elements

Question 46

Why are osmotic diuretics used in the treatment of cerebral edema?

Answer 46

Alter starling's forces to pull water out of cells

Question 47

What is dialysis disequilibrium syndrome?

Answer 47

Too rapid of a removal of solutes from ECF by hemodialysis results in a reduction of osmolality of the ECF, causing a fluid shift into the intracellular compartment

Question 48

How do osmotic diuretics help in dialysis disequilibrium syndrome?

Answer 48

Osmotic diuretics increase the osmolality of the extracellular fluid compartment and thereby shift water back into the extracellular compartment

Question 49

How do osmotic diuretics help with acute attacks of glaucoma?

Answer 49

Increasing osmotic pressure of the plasma, extract water from the eye

Question 50

What are the three adverse effects of osmotic diuretics?

Answer 50

Expand extracellular fluid volume Hyponatremia Hypernatremia

Question 51

What pts are particularly at risk for expansion of ECF volume d/t osmotic diuretics?

Answer 51

heart failure

Question 52

How do osmotic diuretics cause hyponatremia?

Answer 52

Increased extraction of water

Question 53

How do osmotic diuretics cause hypernatremia?

Answer 53

Loss of water in excess of electrolytes

Question 54

Why should pts with impaired liver function not be given urea as an osmotic diuretic?

Answer 54

Increases ammonia level

Question 55

Why should pts with an active cranial bleed not be given mannitol or urea?

Answer 55

Diuretic will leak out of the intravascular compartment

Question 56

Why should hyperglycemic pts not be given glycerin?

Answer 56

Glycerin can be metabolized and cause hyperglycemia

Question 57

What is the MOA of loop diuretics?

Answer 57

Selectively inhibit NaCl reabsorption in the thick ascending loop of henle (NKCC inhibition)

Question 58

Why are loop diuretics so efficacious?

Answer 58

huge absorptive capacity of NaCl in the tubules

Question 59

What are the three loop diuretics?

Answer 59

1. Furosemide 2. Bumetanide 3. Ethacrynic acid

Question 60

What is the effect of loop diuretics on the veins?

Answer 60

Decreased venous pressure

Question 61

Why is it that you lose Ca and Mg with loop diuretics?

Answer 61

Decreasing the lumen positive potential that promotes Ca/Mg reabsorption

Question 62

Why are loop diuretics used for acute pulmonary edema?

Answer 62

Rapid increase in venous capacity and fast natriuresis relieved pressure on the heart

Question 63

Why are loop diuretics used to treat chronic congestive heart failure?

Answer 63

Minimizes pulmonary and venous congestion

Question 64

Why are loop diuretics used for nephrotic syndrome?

Answer 64

Loop diuretics are the only drugs that are able to draw off fluid from the kidneys

Question 65

What are loop diuretics used in liver cirrhosis?

Answer 65

Draw of edema/ascites caused by liver failure

Question 66

Why are loop diuretics used in drug overdoses?

Answer 66

Induce a forced diuresis for rapid renal elimination of the offending drug

Question 67

What are loop diuretics used in hypercalcemia?

Answer 67

Will maintain Ca in the lumen of the nephron, causing loss in the urine

Question 68

Why are loop diuretics used to treat hyponatremia?

Answer 68

they interfere with the kidney's capacity to produce concentrated urine. Using hypertonic saline + loop diuretics

Question 69

What is THE major adverse effect of loop diuretics?

Answer 69

Hypokalemia