Renal Flashcards
which portion of loop of Henle is impermeable to water?
ascending limb
electrolytes Na+/2K+/Cl- are absorbed via cotransport to maintain corticomedullary gradient.
describe water permeability in loop of henle
glomerular capillaries to descending loop (high and passive permeability)
thick and thin ascending loop (impermeable)
early distal convoluted tubule (low)
late distal convoluted to collecting ducts (regulated by vasopressin)
efferent constriction leads to what changes in GFR and FF? why?
some constriction
complete constriction
FF always increased (b/c RPF goes down
GFR increases at first (more time for filter) and then decreases with complete constriction (protein buildup-increased oncotic pressure)
FF=GFR/RPF
filtration fraction= GRF/renal plasma flow
nephron drug that increase urea reabsorption
vasopressin (ADH)- works in meddullary collecting tubules by increasing number of cell suface urea transporters. This contributes to formation of corticomedullary interstitial osmotic gradient
action at nephron of
inulin
paraaminohippuric acid (PAH)
amino acids
- free filtered and not absorbed or secreted. used to estimate GFR. similar to mannitol
- freely filtered and also secreted- used calculate renal plasma flow. similar to creatinine
deposits seen in which renal glomerulonephropathies:
- C3
- C1q
- IgE
- post-streptococcal glomerulonephritis
- MPGN type 1
- lupus nephritis
light microscopy features associated with Goodpastures Alport's syndrome/MPGN type 1 Minimal change disease Membranous glomerulonephropathy
- crescent formation
- lobular appearance with proliferating mesangial cells and increase mesangial matrix
- normal glomeruli
- uniform diffuse capillary wall thickening
renal toxicity associated with acyclovir, how to treat?
crystalline nephropathy-give aggressive intravenous hydration
VHL gene is found in which chromosome, mutation can lead to
3p, renal cell carcinoma
relationship between GFR and Cr, change in Cr when GFR is
- normal
- decreased
- good rule of thumb
- indirect but it’s not linear. more curved graph.
- if GFR is normal then small changes don’t change Cr
- if GFR is low then small changes change CR substantially
- good rule=every time GFR halves, Cr doubles
cells involved in organ rejection
- hyperacute-mins
- acute-week
- chronic-yrs
- preformed antibodies (i.e. ABO mismatch)
- host t-cells sensitization (histo shows dense infiltrate of mononuclear cells)
- host b-celle sensitization with t-cells sensitization
prevention/treatment of organ rejcetion
calcineurin inhibitors (cyclosporine or tacrolimus) or corticosteroids
renal plasma flow equation vs renal blood flow equation
-plasma volume that flow through kidney per unit time
=PAH clearance=(urine PAH * urine flow rate)/ plasma PAH
-the volume of blood that flows through kidney per unit time. the fraction of blood occupied by plasma is (1-hematocrit)
So, RBF=renal plasma flow divided by the fraction of blood occupied by plasma=(PAH clearance)/ (1-hematocrit)*
hypersensitivity of Goodpasture’s vs acute poststreptococcal glomerulonephritis
- type II: antibodies to basement membrane
- type III: immune complex formation
in horseshoe kidney under which artery does fused pole become trapped under
-inferior mesenteric artery
where is lowest concentration of PAH? why?
in boman’s space.
-b/c it is filtered and then actively secreted into nephron
what is important prognostic factor in poststreptococcal glomerulonephritis? why not corticosteroids?
- age, children tend to recovery more than adults
- not corticosteroids b/c they’re not used. this diseases recovers on it’s own
histological appearance:
- membraneous glomerulopathy
- membranoproliferative glomerulonephritis
- berger disease
- minmal change disease
- diffuse increased thickness of BM on LM without increased cellularity, “spike and dome”on silver stain, granular deposits on IF
- LM: large hypercellular glomeruli
- IF: IgA deposits in mesangium
- no abnormalities on LM or IF. only effacement of foot processes is seen in electron microscopy
effect of ureteral constriction or obstruction on GFR, FF, and RPF
- GFR decreases
- RPF remains the same
- FF decreases
without antidiuretic hormone the tubular fluid is most concentrated where? most dilute?
- junction between descending and ascending limbs of the loop of Henle
- collecting ducts
bilateral blood vessels, smooth muscle and fat in kidney-def associated with what disease other findings?
- renal angiomyolipoma
- tuberous sclerosis-AD inheritance
- cortical tubers, subependymal hamartomas in bran (seizures and mental retardation) cardiac rhabdomyomas, facial angiofibromas and leaf-shaped patches of skin lacking pigment (ash-leaf patches)
bilateral renal cell carcinomas is associated with which AD condition. also look for what 3 findings
Von-Hippel-Lindau disease
also look for cerbellar hemangioblastomas, retinal hemangiomas, and liver cysts
modified smooth muscle cells of the afferent and efferent arteriole are aka
JG cells of JG apparatus.
apparatus also contains macula densa cells (tall narrow cells located in distal tubules)-
role of macula densa and JG cells of JG apparatus
-MD monitor osmolarity and volume of urine that pass into distal tubules and transmit information to JG cells where renin synthesis occurs
renal complication of pelvic surgery. not renal cell carcinoma b/c
- ligated ureters esp in hysterectomies
- can lead to hydronephrosis (flank pain that radiates to groin and causes distention (a palpable mass in kidney on deep palpation))
- RCC presents as a painless hematuria, flank pain and palpable mass
what factors increase risk of nephrolithiasis? which diuretic can prevent this? not acetazolamide or furosemide b/c?
stones are precipitated by high tubular concentration of Ca2+
- thiazide diuretics increase Ca2+ reabsorption from nephron by inhibiting Na+/Cl- transporter on apical side decrease Na+ concentrations and increasing Na+/Ca2+ antiport on basolateral membrane. it also causes hypovolemia which increases Na+ and water reabsorption in the proximal tubule along with passive paracellular Ca2+ reabsorption
- can also use potassium citrate to alkalinize the urine
- acetazolamide causes bicarb wasting at proximal convoluted tubule. this leads to metabolic acidosis and worsens hypercalciuria by causing release of calcium phosphate from bone
- loop diuretics blocks transcellular N+/K+/Cl- reabsorption which inhibits paracellular Ca2+ reabsorption
diuretic of choice in acute settings? why? name 3 common toxicities
loop diuretics b/c loop of Henle has significant resorptive capacity
-common side effects include hypokalemia, hypomagnesemia, and hypocalemia
serum IgG4 antibodies to phospholipase A2 receptor
membraneous nephropathy
winter’s formula- def, when is it used?, give example of when metabolic acidosis is not fully compensated for
- PaCO2= [1.5*HCO3-]+8+/-2
- used in metabolic acidosis to check for appropriate respiratory compensation
- sometimes DKA can lead to respiratory failure and lack of Kussmaul respirations
hyperacute rejection-def, hypersensitivity type, 2 examples, diagnosed when and how? organ appearance
medicated by preformed antibodies against antigens on host organ (type II hypersensitivity)
- ABO blood groups and anti-HLA antibodies
- immediately, diagnosed intra-operatively, mottling of organ
immediate hypersensitivity-hypersensitivity type, characterize immune response, give 4 examples
type I hypersensitivity
- IgE class switching on B-lymphocytes
- anaphylaxis, urticaria, asthma and seasonal allergies
mechanism of toxicity with ethylene glycol
- typical findings
- typical pt pop
- acute renal failure due to precipitation of calcium oxalate crystals in renal tubules
- anion gap metabolic acidosis, increased osmolar gap, calcium oxalate crystals in urine
- homeless alcoholic, oligouria, anorexia and flank pain (3 symptoms of acute renal failure)
muddy brown casts
acute tubular necrosis (ATN)