Renal Flashcards
(58 cards)
Although only a transient structure, what is the first functional unit of the kidney to appear?
Mesonephros
What adult structures of the kidney are derived from the mesonephric duct?
Collecting ducts, calyces, renal pelvises, and ureters. All of these derive from the ureteric bud which is an EXTENSION of the mesonephros
What’s the 60-40-20 rule for remembering body fluid?
60% of total body weight is water
of that 40 would be ICF and 20 would be ECF (i.e. 2/3 is intracellular, 1/3 is extracellular)
Of the extracellular fluid, only 1/4 is plasma
What compartment is highest in Mg2+?
Intracellularly
What is the molecular pathogenesis of diabetic nephropathy?
Microalbuminuria results from non-enzymatic glycosylation of the basement membrane eliminating the normal negative charge barrier.
What will you see on glomerular histology in diabetic patients?
Kimmelstiel-Wilson nodules, ovoid or spherical lamellated eosinophilic nodules located in the peripheral mesangium. They also stain PAS+.
Aka nodular glomerulosclerosis
How would diabetic nephropathy be described on histology/path?
Glomerular basement membrane thickening
Increased mesangial matrix deposition
Kimmelstiel-Wilson nodules
What is the equation for clearance?
Cx = UxV/Px
The perfect estimate of GFR is _____, but instead we use _____.
Inulin
Creatinine, even though creatinine slightly overestimates GFR.
What is PAH used to estimate?
RPF
Kidneys receive ___% of CO at rest.
25%
Renal blood flow is approximately ___x the RPF. Why?
2x
because almost or nearly 50% of the blood flow is red cells which does not pass the glomerular BM
What is the typical filtration fraction? GFR/RPF?
Roughly 20%
Which diuretic is a carbonic anhydrase inhibitor? Where does it act and what does it do?
Acetazolamide used in the treatment of acute angle-closure glaucoma and altitude sickness
Inhibits carbonic anhydrase in the PCT preventing NaHCO3 reabsorption -> HCO3- wasting -> metabolic acidosis and alkaline urine
Which diuretic class is contraindicated in patients prone to forming kidney stones?
Loop diuretics (e.g. furosemide) due to increase Ca2+ concentrations in the urine
In these patients thiazides are a better choice
Triamterene and amiloride are K____ diuretics that act on the ____ channel in the _____.
K-sparing
Inhibit ENaC in the principal cells of the collecting tubule
What is Fanconi Syndrome?
Failure of reabsorption in the PCT -> loss of glucose and AA, HCO3-, and phosphate reabsorption most affected
What is Bartter syndrome?
Failure of reabsorption in the TAL -> hypokalemia and metabolic acidosis (like loop diuretics)
Liddle’s syndrome, which is autosomal ____ leads to increased activity of _____.
Autosomal dominant
Overactive sodium channels in the collecting duct
Why does alkalosis cause hypokalemia?
There is a K+/H+ exchanger that will push K+ into cells in order to get H+ out into the bloodstream in an effort to correct pH.
What is the mnemonic for remembering renal tubule disorders (in order from proximal tubule to collecting duct!)?
FABulous Glittering LiquidS
FAnconi - PCT
Bartter - TAL (NKCC)
Gitelman - DCT (NaCC co-transporter)
Liddle - increased ENaC
Syndrome of apparent mineralocorticoid excess (i.e. 11betahydroxy def.)
How do you calculate the anion gap? What is a normal range?
Na - (Cl + HCO3-)
Normal range = 8-12
What is the mnemonic for high anion gap metabolic acidosis?
MUDPILES
Methanol Uremia DKA Propylene glycol Iron tablets Lactic acidosis Ethylene glycol Salicylates (late)
What is the mnemonic for normal anion gap acidosis?
HARDASS
Hyperalimentation Addison disease Renal tubule acidosis Diarrhea Acetazolamide Spironolactone Saline infusion
