B5-037 Renal Physiology II Flashcards
main area where a lot of reabsorption occurs
proximal tubule
70% of the ultrafiltrate
second stage for reabsorption
descending loop of Henle
capillaries of the second capillary bed of the portal system of the nephron
peritubular capillaries
path through the cell
transcellular
path between cells, across zona occludens
paracellular
all salt and water transport in the proximal tubule depends on the gradient generated by
Na/K/ATPase
damage of […] will greatly impair the reabsorptive function of the proximal tubule
Na/K/ATPase
segment involving concentrating or diluting urine
loop of Henle
secondary place for sodium reabsorption
ascending loop of Henle
important transporter at apical side of cells in ascending loop of Henle
Na/K/2Cl
furosemide inhibits […], impairing salt reabsorption in the loop of Henle
NKCC
causes diuresis
[…] is key for the capacity of the kidney to concentrate the urine
transporter
NKCC
loop of Henle
main hormone for regulation of sodium reabsorption
aldosterone
main target of aldosterone effects
sodium transport mechanism
(Na channel + NaKATPase)
distal tubule
increases sodium and water reabsorption, causing an increase in intravascular volume and high blood pressure
hormone
aldosterone
distal tubule
where in the nephron does aldosterone primarily exert its effects?
distal tubule
regulates water reabsorption in the collecting ducts
hormone
ADH
ADH binds to V2 receptors in the collecting duct causing the
phosphorylation of aquaporin2
higher expression of […] at the apical membrane of the collecting duct cells mediates water reabsorption
aquaporin2
low levels of ADH lead to intense
polyuria
less phosphorylation of AQ2
glucose and amino acids are absorbed 100% in the
proximal tubule
most Mg2+ is reabsorbed in the
loop of Henle
most important cation in determination of ECF osmolarity
sodium
main organ that maintains natriemia
kidney
thiazides inhibit […] in the distal tubule
NaCl costransporter
water not reabsorbed, more urine volume
apical sodium channel in collecting tubule
ENac
apical side transporters of proximal tubule
4
- Na-glucose cotransporter
- Na-amino acid co transporter
- NaH antiporter
- Na Channels
basolateral side transporters of proximal tubule
2
- NaKATPase
- Na-bicarb cotransporter
apical side transporter of loop of Henle
NKCC cotransporter
basolateral side transporter of loop of Henle
NaKATPase
apical side transporter of distal tubule
NaCl cotransporter
basolateral side transporter of distal tubule
NaKATPase
apical side transporter of collecting duct
ENac
basolateral side transporter of collecting duct
NaKATPase
follows Na+ and is regulated by the agents that regulate Na+
chloride
postassium is mainly
intracellular or extracellular
intracellular
sodium is mainly
intracellular or extracellular
extracellular
main organ for excretion of potassium
kidney
handling of K+ in the proximal tubule is mainly through
tight junctions
main transporter for potassium in loop of Henle
NKCC
main factor that regulates potassium secretion
aldosterone
basolateral calcium transporters throughout nephron
2
Na/Ca exchanger
CaATPase
apical calcium transporter throughout nephron
Ca channel
H2PO4 (phosphate) transport depends on
sodium
proximal tubule
glucose is handled by the
proximal tubule
100%
SGLT-2 inhibitors cause glucose to be extreted through [transporter] on the basolateral side of the cell
GLUT 2
proximal tubule, loose glucose in urine
beyond the level of maximal transport, the excess glucose in the ultrafiltrate will be
excreted
appears in urine
when the mechanism of transport are saturated (maxima transport) […] appears in urine
glucose
an excess of K+ in the diet will trigger excretion via
NaKATPase
principle cells of collecting ducts
NKCC transporter in the loop of Henle is involved in [….] of K+
reabsorption or secretion
reabsorption
in which segment of the nephron does tubular fluid have a greater osmolarity than plasma?
descending loop of Henle
which segment gains salt and loses water as it passes through renal medulla?
descending loop of Henle
in the distal tubule, tubular fluid is […] compared to plasma
hyper or hypotonic
hypotonic
which part of the nephron has an osmolarity similar to plasma?
2
Bowman’s space
proximal tubule
what causes glucosuria?
saturation of the mechanisms that transport glucose in the renal tubules
all salt and water transport in the proximal tubule depens on the the sodium gradient generated by
NaKATPase
how does the glomerular tubular balance respond to an increase in GFR?
higher reabsorption of salt and water
what mechanism plays a primary role in preventing salt waste?
glomerulotubular balance
what contributes to the retention of uric acid in blood?
lower GFR
furosemide inhibits what transporter?
NKCC
how would furosemide effect that fractional excretion of sodium?
increases FENa
inhibits Na+/PO43- cotransport
in PCT
PTH
phosphate is excreted
stimulates the Na+/H+ exchanger
in PCT
angiotensin II
increases Na, H20 and bicarb reabsorption
passively reabsorbs H2O via medullary hypertonicity
descending loop of Henle
impermeable to water
concentrating segment, makes urine hypertonic
descending loop of Henle
- reabsorbs Na+, K+, and Cl-
- indirectly induces paracellular reabsorption of Mg2+ and Ca2+ through K+ backleak
ascending loop of Henle
- reabsorbs Na+, Cl-
- impermeable to H2O
- makes urine hypotonic
DCT
stimulates Ca2+/Na+ exchanger in DCT to promote Ca2+ reabsorption
PTH
reabsorbs Na+ in exchange for secreting K+ and H+
collecting tubule
regulated by aldosterone