Physiology - Tubular function Flashcards
which part of the nephron contributes the most to to reabsorption?
a.PCT
b.renal corpuscle
c.DCT
d.loop of Henle
a.PCT
movement of substances in the spaces between cells down a concentration gradient is known as
a.paracellular
b.transcellular
c.paracrine
d.autocrine
a.paracellular
movement of substances through a cell eg passive diffusion, facilitated diffusion, and active transport is known as
a.paracellular
b.transcellular
c.paracrine
d.autocrine
b.transcellular
one substances [] gradient being used to move another substance is an example of what type of transport
a.passive diffusion
b.facilitated diffusion
c. 1 active transport
b.2 active transport
b.2 active transport
substance moving from the blood to the filtrate is known as
a.reabsorption
b.secretion
c.excretion
b.secretion
substance moving from the filtrate to the blood is known as
a.reabsorption
b.secretion
c.excretion
a.reabsorption
what transporter moves glucose from the filtrate to the PCT?
a.SGLT2
b.GLUT 2
c.GLUT 4
a.SGLT2
sodium glucose co transporter
what transporter moves glucose from the PCT to the blood?
a.SGLT2
b.GLUT 2
c.GLUT 4
b.GLUT 2
what limits the rate of tubular reabsorption of glucose
a.glucose conc
b. sodoium conc
c.rate at which transporters work
d.number of transporters
c.rate at which transporters work
when the maximum rate of glucose resorption is exceeded what happens
a.polydypsia
b.polyuria
c.glucosuria
c.glucosuria
glucose in urine
cannot be reabsorbed
eg reabsorption dysfunction - fanconi syndrome
induced by drugs such as SGLT2 inhibitors
what is amino acid transport limited by
a.speed of pump
b. number of pumps
c.conc of amino acids
a.speed of pump
where is glucose rabsorbed
a.PCT
b.renal corpuscle
c.DCT
d.collecting ducts
e.loop of henle
a.PCT
where are amino acids reabsorbed
a.PCT
b.renal corpuscle
c.DCT
d.collecting ducts
e.loop of henle
a.PCT
how does sodium move from the tubes throughout the nephron to the blood
a. Na/Cl cotransporter
b. Na/K+/Cl- pump
c.Na/AA cotransporter
d.sodium glucose co transporter
e.sodium potassium pump
e.sodium potassium pump
how does sodium move from the filtrate to the PCT
a. Na/Cl cotransporter
b. Na/K+/Cl- pump
c.Na/AA cotransporter
d.sodium glucose co transporter
e.sodium potassium pump
d.sodium glucose co transporter
c.Na/AA cotransporter
how does sodium move from the filtrate to the ascending loop of henle
a. Na/Cl cotransporter
b. Na/K+/Cl- pump
c.Na/AA cotransporter
d.sodium glucose co transporter
e.sodium potassium pump
b. Na/K+/Cl- pump
how does sodium move from the filtrate to the distal convuluted tubule
a. Na/Cl cotransporter
b. Na/K+/Cl- pump
c.Na/AA cotransporter
d.sodium glucose co transporter
e.sodium potassium pump
a. Na/Cl cotransporter
how does sodium move from the filtrate to the collecting ducts
a. Na/Cl cotransporter
b. Na/K+/Cl- pump
c.Na/AA cotransporter
d.sodium glucose co transporter
e. facilitated diffusion
e. facilitated diffusion
aldosterone increases expression of which pump in the DCT and collecting ducts
a. Na/Cl cotransporter
b. Na/K+/Cl- pump
c.Na/AA cotransporter
d.sodium glucose co transporter
e. sodium pottasium
e. sodium pottasium
only in DCT and CD as absorption here is expression limited whereas it is gradient limited in the PCT/Ascending loop
wheredo SGLT2 inhibitors work in hypertension to reduce sodium resorption and therefore blood volume
a.PCT
b.Ascending loop
c.DCT
d.collecting ducts
a.PCT
wheredo loop diuretics work in hypertension to reduce sodium resorption and therefore blood volume
a.PCT
b.Ascending loop
c.DCT
d.collecting ducts
b.Ascending loop
inhibit na/cl/k pump
which transport protein found in the ascending loop is inhibited by loop diuretics
a. Na/Cl cotransporter
b. Na/K+/Cl- pump
c.Na/AA cotransporter
d.sodium glucose co transporter
e. sodium pottasium
b. Na/K+/Cl- pump
which transport protein found in the PCT is inhibited by SGLT2 inhibitors
a. Na/Cl cotransporter
b. Na/K+/Cl- pump
c.Na/AA cotransporter
d.sodium glucose co transporter
e. sodium pottasium
d.sodium glucose co transporter
which transport protein found in the DCT is inhibited by thiazides
a. Na/Cl cotransporter
b. Na/K+/Cl- pump
c.Na/AA cotransporter
d.sodium glucose co transporter
e. sodium pottasium
a. Na/Cl cotransporter
which protein found in the DCT and collecting ducts inhibits the action of aldosterone which usually increases k+ excretion /Na+ reabsorption
a. Na/Cl cotransporter
b. Na/K+/Cl- pump
c.Na/AA cotransporter
d.sodium glucose co transporter
e. sodium pottasium
e. sodium pottasium
which route is water reabsorbed by in the PCT and descending loop?
a.transcellular
b.paracellular
b.paracellular
between cells down conc gradient following sodium
which route is water reabsorbed by in the DCT and collecting ducts ?
a.transcellular
b.paracellular
a.transcellular
through cells via aquaporins
ADH increases number of aquaporins INSERTING into membrane of tubule cells and so increases water absorption
ADH increases the insertion of aquaporin channels into which parts of the nephron
a.PCT and descending loop
b.DCT and ascending loop
c.DCT and collecting ducts
d.PCT and collecting ducts
c.DCT and collecting ducts
limbs of the loop of henle are arranged with flow in the ………… direction to that of the vasa recta
a.same
b.opposite
b.opposite
counter current mechanism
6 stages that make up the counter current mechanism
sodium pumped out of ascending limb of LOH into interstitium , this sodium then diffuses into the descending vasa recta
this high sodium conc. blood moves along vasa recta to ascending vasa recta
this draws water out from the descending limb of the loop of henle and into the ascending vasa rectae (water follows sodium)
as filtrate moves from the descending loop of henle to the ascending LOH it has lost water and is v concnetrated with sodium
At ascending LOH sodium is moved out of the lumen and into the vasa recta to repeat the cycle
what is the net effect of the counter current mechanism between the loop of henle and the vasa recta
a.sodium reabsorbed, water excreted
b.sodium and water reabsorbed
c.sodium and water excreted
b.sodium and water reabsorbed
what is polyuria
a.increased frequency of urination
b.increased volume of urine
c.increased concentration of urine
d.increased thirst
b.increased volume of urine
what is polydipsia
a.increased frequency of urination
b.increased volume of urine
c.increased concentration of urine
d.increased thirst
d.increased thirst
what happens to blood osmolarity in diabetes
a.increase
b.decrease
c.no change
a.increase
the max production rate for which hormone is exceeded in diabetes mellitus
a.insulin
b.glucagon
c.ADH
d.CRH
c.ADH
max aquaporin insertion but still water remains in tubules as glucose remains in tubules keeping it in (osmosis)
where is urea filtrered
a.pct
b.dct
c.renal corpuscle
d.bowmans capsule
d.bowmans capsule
what happens to urea at the proximal convuluted tubule
a.reabsorbed via passive diffusion
b.secreted
c.reabsorbed
a.reabsorbed via passive diffusion
what happens to urea at the loop of henle
a.reabsorbed via passive diffusion
b.secreted
c.reabsorbed
b.secreted
what happens to urea at the collecting ducts
a.reabsorbed via passive diffusion
b.secreted
c.reabsorbed
c.reabsorbed
contributes to hyperosmolarity in medullary interstitium
ability to eliminate all urea is sacrificed in order to prioritise water reabsorption
when substances are removed from the interstium or blood regardless of whether it is filtered at the glomerulus
a.reabsorption
b.secretion
c.excretion
b.secretion
eg elimination of metabolites /toxins/drug clearance
what is tubular secretion measured with clearance of which substance
a.creatinine
b.PAH
b.PAH