Absorption and Secretion

Question 1

the use of ATP directly for active transport is known as what?

Answer 1

primary active transport

Question 2

the use of ATP indirectly to form an ion gradient for active transport is known as what?

Answer 2

secondary active transport

Question 3

Na+/K+ ATPase, H+ ATPase, H+/K+ ATPase, and Ca2+ ATPase are examples of what kind of transporters?

Answer 3

primary active transporters

Question 4

Na+/glucose co-transporters (SGLT1, SGLT2) and Na+/H+ exchanger (NHE) are examples of what kinds of transporters?

Answer 4

secondary active transport

Question 5

what are the two main pathways that substances moves across the tubular epithelia into the renal intersitial fluid?

Answer 5

paracellular and transcellular pathways

Question 6

tubular reabsorption in which substances cross peritubular capillary membranes back into the blood is known as what?

Answer 6

bulk flow

Question 7

what forces mediate bulk flow?

Answer 7

hydrostatic and colloid osmotic forces

Question 8

transcellular movement can either be via _______ ________ or ______ ______

Answer 8

passive diffusion or active transport

Question 9

in the proximal tubule Na+/K+ ATPase on basolateral side pumps Na+ ____ of the cell and K+ _____the cell to create charge of ____ mV in cell

Answer 9

out, in, -70

Question 10

in the proximal tubule the passive diffusion of Na+ from the lumen into the cell is due to what two factors?

Answer 10

the concentration gradient of Na+ and the negative intracellular potential

Question 11

what two things are reabsorbed due to co-transport with Na+ and what kind of transporters are used?

Answer 11

AA and glucose via secondary active transporters

Question 12

approximately what % of reabsorption occurs in the proximal tubule?

Answer 12

65%

Question 13

what two major organic compounds are almost completely reabsorbed by the FIRST HALF of the proximal tubule?

Answer 13

Na+ co-transport with glucose, AA

Question 14

what major reabsorption occurs in the SECOND HALF of the proximal tubule?

Answer 14

Na+ co-transport with Cl-

Question 15

in the proximal tubulue the amount of Na+ decreases along it’s length but the conc remains constant, why?

Answer 15

because water moves with sodium, conc therefor doesn’t change

Question 16

what is the glucose threshold in plasma?

Answer 16

200 mg/dL

Question 17

which occurs first, glucose threshold or glucose transport maximum?

Answer 17

glucose threshold

Question 18

glucose in urine is known as….

Answer 18

glucosuria

Question 19

when would glucosuria occur?

Answer 19

DM or a non-diabetic having a large sugar rich-meal in a high stress situation

Question 20

roughyl what precent of uric acid is reabsorbed?

Answer 20

90%

Question 21

what condition occurs when uric acid reabsorption is excessive and blood urate levels become elevated?

Answer 21

gout

Question 22

excretion of uric acid can be enhanced by what class of drugs to treat gout?

Answer 22

uricosurics

Question 23

what do uricosurics do?

Answer 23

block the reabsorption of uric acid

Question 24

name three common uricosurics

Answer 24

Probenecid, Benzbromarone, and Sulfinpyrazone

Question 25

what drugs inhibit carbonic anhydrase in cells and in lumen, blocking NaHCO3 recovery?

Answer 25

Carbonic anhydrase inhibitors

Question 26

the descending loop is highly permeable to reabsorption of what?

Answer 26

water and most solutes

Question 27

the thin ascending loop is permeable and imperermable to reabsorption of what?

Answer 27

impermeable to water (water can't leave) and slightly soluble to some solutes but less than the thick ascending loop

Question 28

the thick ascending loop is permable and impermable to the reabsorption of what?

Answer 28

impermeable to water (water can't leave) and permeable to most solutes such as Na+, K+, Cl-, Ca2+, bicarbonate, Mg2+

Question 29

what class of drugs inhibit action of Na+/2Cl-/K+ co-transporter in the thick ascending loop of henle?

Answer 29

loop diuretics

Question 30

since loop diuretics Inhibit action of Na+/2Cl-/K+ co-transporter in the thick ascending loop they ______Na+, Cl-, and K+ excretion and ______ water reabsorption

Answer 30

increase and decrease

Question 31

volume depletion, hypokalemia, and hyponatremia are side effects of what class of drugs?

Answer 31

loop diuretics

Question 32

what class of drugs inhibit the action of Na+/Cl- co-transporter in the distal tubule?

Answer 32

thiazide diuretics

Question 33

what are the two main cell types that make up the late distal tubule and cortical collecting tubule?

Answer 33

principal and intercalated cells

Question 34

what cells in the late distal tubule and cortical collecting tubule reabsorb Na+ and water but secretes K+ into the lumen?

Answer 34

prinicpal cells

Question 35

what cells in the late distal tubule and cortical collecting tubule reabsorb K+ and secrete H+ into the lumen?

Answer 35

intercalated cells

Question 36

what are the two major classes of K+ sparing diuretics?

Answer 36

aldosterone antagonists and Na+ channel blockers

Question 37

What do aldosterone antagonists do?

Answer 37

block aldosterone which decreases the expression of Na+/K+ ATPase and other channels, thus retaining K+

Question 38

what to Na+ channel blocker do?

Answer 38

block Na+ channels which are the driving force for K+ secretion, thus retaining K+

Question 39

where is the final site for urine processing?

Answer 39

the medullary collecting duct

Question 40

water permeability in the medullary collecting duct is controlled by what hormone?

Answer 40

ADH

Question 41

is the medullary collecting duct permeable to urea?

Answer 41

yes

Question 42

The medullary collecting duct is very important for the secretion of what ion that is key in acid-base regulation?

Answer 42

H+

Question 43

what class of drugs increases osmolarity of tubular fluid and inhibits water and solute reabsorption?

Answer 43

osmotic diurteics

Question 44

Proximal tubules are active in the SECRETION of many ________

Answer 44

organic acids and bases

Question 45

p-Aminohippuric acid (PAH) is so readily secreted that >___% is cleared from blood in one pass through kidneys

Answer 45

90