Intro renal Flashcards
all nephrons are composed of _____ epithelium
simple
apical membrane faces the _____
lumen
basolateral membrane faces the _____
ECF
what are the apical membrane and basolateral membrane separated by
tight junctions
another name for tight junctions
zonula occludens
what do renal epithelia never contain
gap junctions
what is paracellular transport
solute moving across epithelium by going around the cells & through tight junctions
what is transcellular transport
solute moving across epithelium by going through the cells (crossing both the apical & basolateral membranes)
why are tight junctions important
they determine permeability
tighter epithelium = _____ TEPD
greater
uniport membrane transporter
facilitated diffusion OR primarily active transport (if ATPase pump)
of a single type of solute
symport (coupled membrane transporter)
secondarily active transport
2 different solute types move in the same direction
antiport (coupled membrane transporter)
secondarily active transport
2 different solute types move in opposite directions
another name for symport
co-transport
another name for antiport
exchanger
3 important renal co-transporters (symports)
SGLT
NKCC
NCC
SGLT function
renal co-transporter
3 isoforms: SGLT1, 2, 3
SGLT1 - requires 2 Na+ to move 1 glucose
SGLT2,3 - require 1 Na+ to move 1 glucose
NKCC function
renal co-transporter
uses Na+ gradient to accumulate Cl- & K+ intracellularly
SGLT location
SGLT1 - in later proximal tubule where [glucose] is lower
SGLT2,3 - in early proximal tubule where [glucose] is high
NKCC location
NKCC1 - on basolateral membrane of non-renal epithelia & non-epithelial cells
NKCC2 - on apical membrane of thick ascending limb
NKCC2 is a target for what
one class of loop diuretic
NCC function
renal co-transporter
NCC location
on apical membrane in early distal tubule cells
NCC is a target for what
a class of diuretics