Muster - Loop of Henle, Distal Tubule & Cortical Collecting Duct Flashcards
what type of cancer is known for causing a proximal tubular dysfuction
Multiple Myeloma
what is one classic finding (classical diagnostic tool) in someone with proximal tubule dysfunction
spilling of bicarbonate into the urine until it hits an equilibrium
then if you give them bicarb, it throws off the equilibrium and the pH in the urine starts to rise
can also look for elevated urine glucose in a person with normal blood glucose, can also look for AAs
Ingestion of this can cause proximal tubule dysfuciton
lead
what is the best equation for estimating creatinine clearance
Cockcroft-Gault
orthostatic hypotension is a sign of what
volume depletion
key function of the ascending loop of henle
reabsorbs sodium without resorbing water
what part of the renal tubule is ONLY permeable to water
descending limb
so the osmolality is greatest in the lowest part of the medullary space at around 1400mOms
cells in the ascending limb look like
big and simple cuboidal
part of the renal tubule that is not permeable to water
ascending limb
where are the NKCC pumps in the renal tubule
what ion is moving down its EC gradient
lumen side in the cells of the ascending limb
sodium is moving down its electrochemical gradient
about a third of the sodium that is reabsorbed in the ascending limb moves through the _____
how
pericellular space
its because the Cl- attracts it there (Cl- pumped over via the NKCC pump)
bartter syndrome
nonfunctional NKCC pump (lisinopril blocks this)
mental retardation volume depletion hypokalemia metabolic alkalosis hypercalcURIA
where are the NaCl channels in the renal tubule
in the distal tubule (in the cortex)
Gitleman syndrome
genetic mutation in the NaCl transporter (HCTZ, chlortalidone block this)
normal BP metabolic alkalosis hypocalcURIA hypomagnesemia hyopkalemia
what is a potassium sparing diuretic
two classes and two examples from each
CLASSICLY:
epithelial sodium channel (ENac) blockers:
Amiloride
Triamterene
or
an aldosterone antagonist (don’t work on just ENac):
Spironolactone
Eplerenone
K STAys
Spironolactone, Triamterine, Amiloride
what can happen after you are taken off a diuretic
when you are on the diuretic, your kidney recognizes it as a drop in volume.
When taken off the diuretic the kidney freaks out and takes up even more sodium than you got them off of with your diuretic.
AKA the pendulum swings back too far
What is the best time to give a diuretic
after a bid salt meal.
if their diuretic wears off just before they eat a lot of salt, the rebound effect will cause an even greater retention of sodium
where is the only place in the kidney that you can have variable and controllable sodium reabsorption
collecting tube
epithelial sodium channel
faces what side of cell - lumen or vessel
(ENac)
lumen
Renal outer medularry potassium channel
ROMK
just allows potassium to flow back into the lumen of the renal tubule (as the K concentration increases in the tubule cell from the activity of the Na/K antiporter
fixed amount of sodium that we resorb
95%
(can only control 5% of your filtered load)
you can maximally get rid of about 5% (50g) of this per day, 95% is always absorbed
filtered load equation and normal value for sodium
GFR * [Na]plasma
around 25,000mM/day. (1Kg/day)
1g=25mM
juxtaglomerular cells release what
renin
they are in the afferent arteriole
why does the distal tubule come back and run next to the afferent arteriole
so that the juxtaglomerular cells can detect:
distal flow rate
Na and Cl delivery
so that they juxtaglomerular cells can tell the distal tubule if they are receiving less stretching. this causes production of renin
