kidneys 2 Flashcards
(27 cards)
what order does plasma go through kidney?
bowmanns capsule, proximal tubule, loop of henle, distal tubule, collecting duct
what is filtered in glomerular filtration?
blood plasma (20% removed)
permits H20 and small molecules
restricts blood cells and proteins
what does ultrafiltrate consist of?
protein free plasma
(1% protein filtered- albumin)
conc of Na in bowmanns capsule is same that is in plasma
what is difference between trancellular and paracellular transport ?
transcellular is through cell (requires membrane transport proteins)
paracellular is between cells
what does proximal tubules reabsorb?
70% filtrate
70% H2O and NA
~100% glucose and amino acids
90% HCO3- (bicarbonate)
give transport proteins on apical side
SGLT1, SGLT2, NaPiII
NHE3?
what happened in NaPiII knockout mice?
less phosphate in serum (less reabsorbed) (more in urine)
low phsophate = less dense bone
what is apical and basolateral ?
apical is lumen of tubules, baslateral is peritubular capillaries
what is SGLT1 and SGLT2 structure?
1-664 aa (14 TMD)
2-672 aa
(glocose and sodium reabsorbtion)
what happens in familial renal glycosuria?
increase in urinary glucose
normal plasma glucose
(due to 21 mutations in SGLT2)
what happens in NHE3 knockout mice ?
lower plasma HCO3-
plasma PH decreases (more acidic)
BP decreases
(inhibition of H+ secretion ) causes inhibitions of Na and Hco3- transport
what does loop henle do?
regulates urine conc
reabsorbs Na+, Cl-, and H2O
reabsorbs Ca2+ and Mg2+
site of action of loop diuretics
what are structures of loop diuretics and what do they do?
thin descending limb (reabs of H2O)
thin ascending limb (reabs of Na+, Cl-)+ urea (not permeable to water)
thick ascending limb (reabs Na+ Cl-) (extremely impermeable to H2O)
what are thick ascending limb carriers?
NKCC2, ROMK (apical)
CLCK with Barttin (basolateral)
what is bartters syndrome?
genetic inheritance - recessive slat wasting and polyuria hypotension hypokalaemia higher PH hypercaluciuria
what is mutated in bartters syndrome?
barttin mutated (CLCK doesnt work) this causes increased cellular Cl-, NKCC2 diesnt work
what happens in ROMK mouse ?
polyuria, salt wasting, BUT plasma PH lower than n bartters (acidosis) little/no diff in K+ (no hypokalaemia)
what does early distal tubule do?
reabsorb Na+ and Cl-
Reabsorption Mg2+
is sensitiv to thiazide diuretics
what are carriers on early DT?
apical - NCC + Mg
basolateral - CLCK, an barttin (+na k pump)
what is gitelmans syndrome?
inherited - recessive, salt wasting + polyuria hypotension hypokalaemia higher PH hypocalciura (same as battins expect hypocalciuria)
what causes gitelmans?
loss of function mutation in NCC (less Na and H2O reabsorbed)
what can chlorothiazide do?
can be used to treat high blood pressure
similar syptom to gitelmans
acts on DT
what does late DT , connecting tubules and collecting duct do?
concentrated urine
rabsorption of Na and H2O
secretion of K+ and H+
what are cells types in LDT and CCD?
principle - Na+ and H2O reabsorption.
K+ and H+ secretion
intercalated- alpha and beta
H+ secrestion and reabsorption
HCO3- reabsorption and secretion
