Kidney Structure and Function 2/3

Question 1

how much fluid does the nephron filter per day in a normal person?

Answer 1

180l

Question 2

what does sodium transport facilitate?

Answer 2

reabsorption of nutrients, water and ions

Question 3

how much is reabsorbed in the proximal convoluted tubule?

Answer 3

65%

Question 4

how much is reabsorbed in ascending loop of Henle

Answer 4

25%

Question 5

how much is reabsorbed in the distal convoluted tubule?

Answer 5

up to 8%

Question 6

what is the main site of reabsorption?

Answer 6

the proximal convoluted tubule

Question 7

what do the cells of the PCT have on them?

Answer 7

microvilli to increase surface area for reabsorption

Question 8

what blood vessels do all parts of the nephron have a close relationship with?

Answer 8

the peritubular capillaries

Question 9

what is the blood leaving the efferent arterioles devoid of?

Answer 9

nutrients, ions and water

Question 10

what is passive diffusion?

Answer 10

movement of molecules from high to low concentration until equilibrium is reached

Question 11

how does water move?

Answer 11

via aquaporins

Question 12

what do glucose and amino acids require to move across the apical surface?

Answer 12

co-transporters

Question 13

what are glucose and amino acids co-transported with?

Answer 13

sodium

Question 14

where does the sodium/potassium pump sit

Answer 14

on the basolateral membrane

Question 15

what is the ratio of sodium to potassium that is co-transported?

Answer 15

3 sodium out and 2 potassium in

Question 16

what direction of the concentration gradient does sodium move?

Answer 16

against the concentration gradient

Question 17

what does the sodium/potassium pump mean for the kidney?

Answer 17

it can increase absorption of nutrients from the filtrate

Question 18

what is the relation between water and sodium?

Answer 18

water follows sodium wherever it goes i.e. osmosis

Question 19

what is the relation between glucose and amino acids and sodium?

Answer 19

glucose and amino acids are co-transported with sodium

Question 20

what is the relation between chloride and negative ions and sodium?

Answer 20

chloride and negative ions follow sodium down the electrical gradient

Question 21

what does sodium active transport facilitate?

Answer 21

100% nutrient reabsorption, 65% water reabsorption, 65% negative ions follow electrical gradient, no effect on waste removal

Question 22

whereabouts does the sodium/potassium pump take place?

Answer 22

the PCT

Question 23

what do the juxtamedullary nephrons form?

Answer 23

the counter-current multiplication

Question 24

what limb of the loop of henle has actively pumping sodium/potassium pumps?

Answer 24

thick ascending limb

Question 25

what does the thin descending limb contain that the thick and thin ascending limbs do not?

Answer 25

aquaporins

Question 26

is the thin descending limb permeable to water?

Answer 26

yes

Question 27

are the thick and thin ascending limbs permeable to water?

Answer 27

no

Question 28

what is the thick ascending limb the site of?

Answer 28

active sodium reabsorption

Question 29

what is the ratio of sodium to chlorine and potassium moving from the tubule lumen to the tubule wall in the thick ascending limb?

Answer 29

for every 1 molecule of sodium transported there are 2 chlorine and 1 potassium molecule transported in the same direction

Question 30

what happens to water in the thin descending limbs?

Answer 30

it moves out of the tubule and into the salty medulla

Question 31

what happens to the concentration of the filtrate as it descends the thin descending limb?

Answer 31

it becomes less concentrated

Question 32

why does the concentration in the loop of Henle never equalise?

Answer 32

due to the structure and the fact that new watery fluid is constantly entering and salt is being pumped out and also the structure of the vasa recta

Question 33

what happens to the concentration of the filtrate as it ascends the thick ascending limb?

Answer 33

it becomes even less concentrated

Question 34

what does the vasa recta do?

Answer 34

employ counter current exchange (maintains concentration gradient of the medulla)

Question 35

why does the loop of Henle employ counter current multiplication?

Answer 35

to reabsorb water and concentrate urine

Question 36

which does the thick ascending limb do?

Answer 36

actively reabsorb sodium

Question 37

what is the function of the loop of Henle?

Answer 37

create and maintain high osmotic pressure within the medulla

Question 38

what is the function of the vasa recta in the medulla?

Answer 38

to support the concentration gradient

Question 39

what is the distal convoluted tubule?

Answer 39

the site of fluid volume and electrolyte regulation

Question 40

what does ADH do in the DCT?

Answer 40

increase water reabsorption

Question 41

what does aldosterone do in the DCT?

Answer 41

increase sodium reabsorption

Question 42

what does ANH do in the DCT

Answer 42

promote sodium secretion

Question 43

what happens in the DCT regarding water?

Answer 43

water stays within filtrate and a large volume of dilute urine is produced

Question 44

what state is the tubule fluid entering the DCT in?

Answer 44

it is hypotonic with the interstitium

Question 45

what happens in the absence of external hormonal regulation?

Answer 45

a large volume of dilute urine is produced

Question 46

what is the target site of ADH?

Answer 46

DCT and collecting tubules

Question 47

what does aldosterone do?

Answer 47

upregulates activity and insertion of sodium potassium pumps and channels

Question 48

what does aldosterone act on?

Answer 48

distal and collecting tubules

Question 49

what does ANH do?

Answer 49

inhibits action of ADH and aldosterone

Question 50

what does ANH act on?

Answer 50

distal and collecting tubules

Question 51

what does ADH do?

Answer 51

insertion of aquaporins allows water to be reabsorbed from the filtrate

Question 52

how much of the filtrate is reabsorbed?

Answer 52

99%

Question 53

summarise what the loop of henle does

Answer 53

resorbs water and concentrates filtrate

Question 54

summarise the actions of ADH and aldosterone

Answer 54

they act distally to fine tune the filtrate

Question 55

where does 2/3 of the reabsorption take place?

Answer 55

in the PCT