Jan3 M2-Tubular function

Question 1

daily urine production

Answer 1

1.5L

Question 2

renal perfusion fraction (renal blood flow over cardiac output)

Answer 2

20%

Question 3

PCT function

Answer 3

most reabso

Question 4

loop of Henle fct

Answer 4

salty interstitium

Question 5

CD fct

Answer 5

reabso or secretion of K, Na and acid

reabso (or not) of H2O

Question 6

secretion def and stuff comes from where

Answer 6

from blood to tubules. from peritubular capillaries

Question 7

nephron blood flow

Answer 7

AA, glom caps, EA, along nephron, peritub caps, venous drainage

Question 8

Na in PCT

Answer 8

(60%) Na K ATPase on basolateral side so Na comes in via cotransporters and exchangers on luminal side

Question 9

water in PCT

Answer 9

(60%) osmotic flow out of tubules via aquaporins or tight junctions (between cells)

Question 10

glucose in PCT

Answer 10

(99%) via Na-glucose cotransporter (SGLT2) at lumen and via GLUT2 at basolateral

Question 11

PO4 in PCT

Answer 11

(99%) via Na-PO4 cotransporter

Question 12

a.a in PCT

Answer 12

(99%) via Na-a.a cotransporter

Question 13

Ca in PCT

Answer 13

flows down conc gradient

Question 14

K in PCT

Answer 14

flows down conc gradient in tight junctions

Question 15

Cl in PCT (2)

Answer 15

flows down conc gradient via Cl-base exchanger (lumen) and Cl-K cotransporter (basolateral)
OR tight junctions

Question 16

HCO3 in PCT

Answer 16

(90%) via Na-H exchanger

Question 17

how HCO3 reabsorbed in PCT

Answer 17

1. H20 + CO2 in the cell give H and HCO3 via CA and HCO3 enters the body
2. NH4 or H+ exit cell via Na-H or NH4 exchanger
3. outside, H joins base that exited via Cl base exchanger. Hbase
4. Hbase can enter cell and H can separate from base and reexit.

Question 18

why glucosuria in diabetics

Answer 18

maximal tubular reabsorption (Tmax) is reached. (SGLT2 reaches its max)

Question 19

glucosuria (3 ex of conditions where it’s seen)

Answer 19

diabetics, normal people with low SGLT2 amount, pregnant woman (pregnancy = high GFR)

Question 20

2 components of water regulation in the nephron

Answer 20

1. high osmotic gradient in medullary interstitium

2. ADH action in CD for aquaporins insertion

Question 21

tDL fct (t thin T thick)

Answer 21

permeable to water

Question 22

TAL fct

Answer 22

NaK ATPase on basolateral side. Na out of tubule via Na-K-2Cl cotransporter

Question 23

loop of Henle other fct

Answer 23

Ca, Mg reabso in tight junctions

Question 24

loop of Henle channels

Answer 24

baso: NaK ATPase and Cl channel (Cl back in blood)
lumen: Na-K-2Cl cotransporter and ROMK (renal outer medullary K channel) for K out and for cotransporter not to run out of K)

Question 25

distal tubule 2 main fcts

Answer 25

reabso of Na, Cl and Ca

Question 26

distal tubule: how Na reabso works

Answer 26

NaK ATPase (baso) and then Na enters with Na channel (lum) or Na-Cl exchanger (lum)

Question 27

Cl in distal tubule

Answer 27

moves with Na at lumen via Na-Cl exchanger. 
Cl channel (baso)

Question 28

Ca in distal tubule

Answer 28

NaK ATPase (baso) drives Na Ca exchanger (baso). Ca enters cell via Ca channel (lum)

Question 29

hormones and drugs in distal tubule

Answer 29

thiazides act on Na-Cl cotransporter (lum)

PTH acts on Ca channels (lum)

Question 30

3 cell types in collecting tubules

Answer 30

principal cells, alpha and beta intercalated cells

Question 31

Na in collecting tubules

Answer 31

principal cells, Na K ATPase (baso) and Na channel (lum) both controlled by aldo

Question 32

K in collecting tubules

Answer 32

channels (lum andd baso) to let it out of the cell (to tubule or interst)

Question 33

acid base balance where in the CT

Answer 33

alpha (mainly) and beta intercalated cells

Question 34

H2O in CT

Answer 34

under ADH control: allows insertion of aquaporins

Question 35

2 tissue origins of the nephron and cell type + structure of each

Answer 35

ureteric bud (tubule, epithelial) and metanephric bud (glomeruli. endothelium. but podocytes are epith)