Distal Segment Transport

Question 1

what is the name of the diuretic that inhibits the NCLK channel in the loop?

Answer 1

furosemide

Question 2

barterrs syndrome is a defect of what?

Answer 2

NKCC channel

Question 3

name the four molecular changes with Barterrs syndrome

Answer 3

hypokalemia, metabolic alkalosis, polyuria, dehydration

Question 4

what is the name of the cotrasnported on the luminal surface of the early distal tubule?

Answer 4

sodium chloride cotransporter (NCC)

Question 5

what drives the flow of sodium in the cell in the early distal tubule?

Answer 5

Na/KATPase

Question 6

what molecule moves into luminal surface of late distal tubule?

Answer 6

just sodium

Question 7

what is the name of the sodium channel in the luminal side of the late distal tubule?

Answer 7

ENaC

Question 8

what molecule goes out of the luminal side of the late distal tubule?

Answer 8

potassium

Question 9

name the two cell types in the late distal tubule

Answer 9

alpha and beta intercalated cells

Question 10

what is the main role of alpha intercalated cells?

Answer 10

acid base homeostasis

Question 11

what molecule is pumped out into lumen in the alpha intercalated cells?

Answer 11

H+

Question 12

name the two H+ channels in the luminal surface of the late distal tubule

Answer 12

H+ ATPase

H+/K+ ATPase antiporter

Question 13

what transporter does not function in Gitelmans syndrome?

Answer 13

loss of function in the NCC transporter

Question 14

what is the channel change in the Gordons syndrome?

Answer 14

gain of function in NCC transporter

Question 15

what is the channel change in Liddles syndrome?

Answer 15

gain of function in ENaC

Question 16

what is the channel change in pseudohypoaldosterism type I?

Answer 16

loss of function ENaC

Question 17

what type of channel and what location does aldosterone lead to?

Answer 17

ENaC in the distal tubule

Question 18

what molecule goes through the ENaC?

Answer 18

sodium

Question 19

which molecule does the ENaC create a favorable excretion gradient for?

Answer 19

K+

Question 20

name the exchanger on the baso lateral side of the alpha intercalated cells in the distal tubules

Answer 20

bicarb and chloride

Chloride in and bicarb out to interstitium

Question 21

what is the main role of the alpha intercalated cells?

Answer 21

secrete H+

Question 22

what is the main role of the beta intercalated cells?

Answer 22

secrete bicarb and save H+

Question 23

what channel do thiazide diuretics target?

Answer 23

inhibit the NCC

Question 24

what channel do amiloride and triamterene target?

Answer 24

the ENaC

Question 25

does Gitelmans lead to metabolic acidosis or alkalosis?

Answer 25

alkalosis

Question 26

does gitelmans lead to hyper or hypokalemia?

Answer 26

hypokalemia

Question 27

does gordons lead to metabolic acidosis or alkalosis?

Answer 27

acidosis

Question 28

does gordons lead to hyper or hypokalemia?

Answer 28

hyperkalemia

Question 29

does Liddles lead to metabolic acidosis or alkalosis?

Answer 29

alkalosis

Question 30

does Liddles lead to hyper or hypokalemia?

Answer 30

hypokalemia

Question 31

does pseudohypoaldosteronism lead to hyper or hypokalemis?

Answer 31

hyper

Question 32

more sodium in distal segments lead to what two molecules being excreted more?

Answer 32

potassium and H+

Question 33

can the early distal tubule respond to hormones?

Answer 33

no

Question 34

what three hormones do the late distal tubule and collecting ducts respond to?

Answer 34

aldosterone ADH ANP

Question 35

what two channel types does aldosterone lead to?

Answer 35

ENaC and K+ on luminal surface

Question 36

what molecule does ADH bind initially in the nephrons?

Answer 36

vasopressin receptor

Question 37

what does ADH insert in the luminal surface of the DCT or CD?

Answer 37

aquaporin 2

Question 38

what effect does aldosterone have on the intercalated cells in the distal tubule?

Answer 38

increases the H+ ATPase activity...so more H+excreted

Question 39

in the medullary collecting duct, other than water was does ADH lead to reabsorption of?

Answer 39

urea

Question 40

where is urea reabsorbed?

Answer 40

medullary collecting duct

Question 41

what is the osmotic signal that leads to increase in ADH? what receptor senses this?

Answer 41

hyperosmotic | osmoreceptors

Question 42

name the two nonosmotic things that lead to ADH release?

Answer 42

low effective capillary flow volume | low BP

Question 43

why is pseudohypoaldosteronism the only salt losing tubulopathy that leads to hyponatremia?

Answer 43

because it is a defect the ENaC and this is the last place for easy reabsorption of Na

Question 44

how does ADH lead to urea reabsorption?

Answer 44

activated the UT-1 or urea transporter 1 in the medullary collecting duct

Question 45

what is the location of aquaporin 1?

Answer 45

proximal tubule and descending portion of loop...apical side

Question 46

what is the location of aquaporin2 ?

Answer 46

distal tubule and collecting ducts...apical side

Question 47

what is the location of aquaporin 3?

Answer 47

distal tubule and collecting duct...basolateral side

Question 48

when is ANP released? what is the effect it has?

Answer 48

when atrial volume is high...leads to better Na+ excretion