Renal Flashcards
1
Q
nephrotic synd
A
massive proteinuria (>3.5g/day, frothy urine), hyperlipidemia, fatty casts, edema; ass. w/ thromboembolism (bc of ATIII loss in urine; present w/ flank pain + hematuria), increase risk of infection NO RBC OR RBC CASETS IN URINE
FSGS membranous nephropathy minimal change dz (lipoid nephrosis) amyloidosis - ass w/ chronic conditions MPGN diabetic glomerulonephropathy
2
Q
nephritic synd
A
inflammatory!! (hypercellular, inflamed glomeruli from immune-complex dep)
hematuria, RBC casts in urine, azotemia, oliguria, HTN, mild proteinuria
PSGN RPGN DPGN Berger's dz (IgA nephropathy) Alport synd
3
Q
FSGS
A
- segmental sclerosis + hyalinosis (LM)
- effacement of foot processes (EM)
- adults (Hisp, Af Am)
- NO response to steroids
- ass w/ HIV, heroin abuse, obesity, sickle cell dz
4
Q
membranous nephropathy
A
- diffuse capillary + GBM thickening (bc immune-complex dep) (LM)
- “spike-and-dome” appearance w/ SUBEPITHELIAL deposits [b/w epith cells + BM, under podocytes] (EM)
- granular IF (w/ IgG + C3 dep)
- SLE’s nephrotic presentation
- idiopathic (85%)!!
- also by use of NSAIDs/penicillamine, Hep C or B, DM
- Caucasian adults
5
Q
minimal change dz
A
- NORMAL glomeruli (LM)
- foot process effacement - bc of cytokine damage (EM)
- selective loss of albumin, not Ig
- may be triggered by recent infection/immune stim
- children (usually idiopathic)
- responds to steroids (ONLY ONE)
6
Q
MPGN
A
type I:
- granular IF (SUBENDOTHELIAL DEP)
- tram-track appearance bc GBM splitting (from mesangial ingrowth)
- thick capillary membranes
- ass w/ HBV, HCV + subacute bacterial endocarditis
type II:
- INTRAMEMBRANOUS DEP
- ass w/ C3 nephritic factor (auto-Ab stabilizes C3 convertase)
**both have granular IF and LARGE HYPERCELLULAR GLOMERULI
7
Q
diabetic glomerulonephropathy
A
-hyaline arteriosclerosis
-NEG of GBM –> increased permeability, thickening
NEG of efferent arterioles –> increases GFR
GBM thickening, Kimmelsteil-Wilson nodules (ovoid hyaline mass; eosinophilic nodular glomerulosclerosis)
ACE inhibitors slow injury process!!
8
Q
acute post-strep GN
A
- type III HST
- “lumpy-bumpy” appearance (glomeruli enlarged and hypercellular, neutrophils) (LM)
- SUBEPITHELIAL immune complex humps (EM)
- granular IF (IgG, IgM, C3 deposition) - decreased C3, normal C4
- children
- periph + periorbital edema
- dark urine
- after group A-beta strep infection of SKIN (impetigo) or PHARYNX - WEEKS after! + resolves spontaneously
- elevated ASO titers, or anti-DNase B!
9
Q
RPGN
A
- crescent-moon shape (consist of fibrin, plasma proteins like C3b, macrophages, glomerular parietal cells, monocytes) w/in BOWMAN’S SPACE (LM and IF)
- poor prognosis
can result from:
- Goodpasture’s synd (type II HST) - linear IF
- Wegener’s granulomatosis (c-ANCA) - neg IF
- microscopic polyangiitis, Churg Strauss (p-ANCA) - neg IF
10
Q
Goodpasture’s synd
A
type II HST
Ab to GBM and alveolar BM
linear IF (C3 and IgG deposited along GBM)
hematuria/hemoptysis
11
Q
DPGN
A
- due to SLE (most common cause of death in SLE) or MPGN
- “wire looping” of capillaries (LM)
- SUBENDOTHELIAL OR INTRAMEMBRANOUS IgG based immune complexes often w/ C3 dep
- granular IF
12
Q
Berger’s dz (IgA nephropathy)
A
- related to Henoch-Schonlein purpura
- mesangial prolif (LM); mesangial IC dep (EM)
- IgA-based immune complex dep in mesangium (IF)
- NORMAL complement levels
- presents/flares w/ URI or acute gastroenteritis
- follows mucosal infection (bc excess prod of IgA)
- most common nephropathy worldwide
13
Q
Alport synd
A
- mut in type IV collagen –> split BM
- X-linked
- GN, deafness, eye problems (cataracts, etc.)
14
Q
early prox tubule reabsorb/secrete?
A
all of glucose and AA
most of bicarb, Na, Cl, phosphate, water (ISOTONIC absorption)
65-80% Na reabsorbed
secretes ammonia (to buffer H)
15
Q
PTH function in prox tubule
A
inhib Na/phosphate cotransport –> phosphate excretion
16
Q
thin descending LOH function?
A
passive reabsorp of water (via medullary hypertonicity)
concentrating segment –> makes urine HYPERTONIC!
17
Q
thin desc LOH impermeable/permeable to?
A
imperm to Na
perm to urea
18
Q
thick ascending LOH reabsorb?
A
active reabsorption of Na, K, Cl
indirectly reabsorb Mg, Ca (by + lumen potential from K backleak) - paracellular
10-20% Na reabsorbed
19
Q
thick ascending LOH impermeable to?
A
WATER
makes urine LESS concentrated as it ascends
20
Q
early distal convoluted tubule (DCT) reabsorb?
A
ACTIVE reabsorb of Na, Cl (urine hypotonic)
5-10% Na reabsorbed
MOST DILUTE SEGMENT
21
Q
PTH effect on DCT?
A
increase Ca/Na exchange –> Ca reabsorb
22
Q
DCT impermeable to?
A
water (unless vasopressin levels adeq to promote reabsorp) and urea
23
Q
collecting ducts reabsorb?
A
Na in exchange for K, H secretion (reg by aldosterone)
3-5% Na reabsorbed
HYPERTONIC
24
Q
Potter synd?
A
clubfeet flat face w/ low-set ears, other facial deformities pulmonary hypoplasia (most common cause of death)
caused by bilat renal agenesis*** (mostly), ARPKD, posterior urethral valves
25
most bladder cancers are?
transitional cell carcinoma aka UROTHELIAL carcinoma
26
GFR calc measured by?
inulin
| creatinine can estimate
27
PAH best measure of?
RPF; underestimated by ~10%
28
horseshoe kidney trapped under what artery?
IMA
29
RBF =
RPF/(1-hematocrit) = (PAH clearance)/(1-hematocrit)
or (renal artery pressure - renal vein pressure)/renal vascular resistance
30
no ureteric bud =
bilat kidney agenesis
31
horseshoe kidney ass w/ what?
Turner's synd
32
what property of glomerular filtration barrier lost in nephrotic synd?
charge barrier
33
what keeps negative charge barrier?
BM + heparan sulfate
34
renal clearance =
(U x V)/P
35
FF =
GFR/RPF
normally 20%
36
filtered load =
GFR x plasma concentration
37
glucose reabsorpt?
prox tubule via Na/glucose co-transport
@160 mg/dL --> glucosuria (threshold)
@350 mg/dL --> all transporters fully saturated
38
Hartnup disease is?
deficiency of tryptophan --> decreased vit B3 --> pellagra
39
in PCT, ATII action is?
stim Na/H exchange --> increased Na, H2O, HCO3 reabsorption; secrete H
causes contraction alkalosis!
40
TF/P > 1 when
solute absorbed less quickly than water
| ex. PAH, Creatinine, inulin, urea, Cl
41
TF/P = 1 when
solute + water reabsorbed @ same rate
| ex. K, Na
42
TF/P < 1 when
solute reabsorbed faster than water
| ex. HCO3, AA, glucose
43
functions of ATII
potent vasoconstrictor
constricts efferent arterioles --> maintains GFR by increasing FF
stim aldosterone prod, ADH release
increases PCT Na/H activity --> contraction alkalosis
stim hypothal --> thirst
44
ANP effect in kidney
increase GFR
| decrease renin
45
JG cells are modified what?
modified SM of afferent arteriole
46
in renal artery stenosis what happens to JG cells
JG cells of affected kidney(s) --> hypertrophy + hyperplasia bc increased release of renin
47
what part of kidney converts to active vit D
PCT
48
afferent arteriole mediators
prostaglandins - vasodil
| NSAIDS - oppose prostaglandins
49
efferent arteriole mediators
AT II - vasoconstriction
| ACE inhib - oppose AT II
50
protein effects in glomerulus
if increased - increases glomerular capillary oncotic pressure --> decreased GFR, FF; no change RPF
if decreased - decreases glomerular capillary oncotic pressure --> increased GFR, FF; no change RPF
51
impt function of ATII to prevent further decrease in vol loss
compensatory Na reabsorp. @ PCT and DCT!!!
52
increased serum Mg levels -->
decreased DTRs, bradycardia, lethargy, etc.
53
winter's formula
PCO2 = 1.5(HCO3) + 8 +/- 2
54
anion gap =
Na - (Cl + HCO3)
normal = 8-12 mEq/L
55
increased anion gap metab acidosis
```
MUDPILES!
Methanol (formic acid)
Uremia
DKA
Propylene glycol
INH or Iron tablets
Lactic acidosis (ex. in shock)
Ethylene glycol (oxalic acid)
Salicylates (LATE)
```
56
normal anion gap metab acidosis
```
HARDASS!
Hyperalimentation (ex.overeating, parenteral nutrition)
Addison's dz
Renal tubular acidosis
Diarrhea
Acetazolamide
Spironolactone
Saline infusion
```
57
RTA type 1
"distal"
defect in collecting tubule ability to EXCRETE H+ [intercalated cells]
urine pH > 5.5
hypokalemia
increased risk for Ca phosphate kidney stones bc of increased urine pH + bone resorption
58
RTA type 2
```
"proximal"
urine pH < 5.5
defect in PCT reabsorption of HCO3
hypokalemia
increased risk of hypophosphatemic rickets
may be ass w/ Fanconi synd
```
59
RTA type 4
"hyperkalemic"
HYPOALDOSTERONISM or collecting tubule lack of response to aldost
hyperkalemia --> impairs ammoniagenesis in PCT --> decreased buffering capacity + urine pH decreased
60
what 2 synd can present as both nephritic/nephrotic
DPGN
MPGN
SLE
61
diff b/w IgA neph + PSGN
IgA neph - few DAYS after URI infection
| PSGN - few WEEKS after infection
62
complications of kidney stones
hydronephrosis (expansion of renal pelvis)
| pyelonephritis
63
all kidney stones are radiopaque EXCEPT
Uric acid stones = radiolUcent (not seen on x-ray)
| view on CT or US
64
lowest pH in nephrons is @
DCT
| collecting tubules
65
2 factors that prevent crystallization of stones
- citrate (binds free Ca --> facilitates its excretion)
| - fluids!
66
calcium phosphate stones
alkaline pH
causes: hypercalcemia (cancer, increased PTH, sarcoidosis), Crohn's
tx = citrate, thiazide diuretics
67
calcium oxalate stones
acidic pH
**can result from ethylene glycol (antifreeze) or vit C abuse
other causes: hypercalcemia (cancer, increased PTH, sarcoidosis), Crohn's
tx = citrate, thiazide diuretics
68
common kidney stone presentation
calcium oxalate stones in pt w/ hypercalciuria + normal serum calcium (idiopathic hypercalciuria)
69
ammonium magesium phosphate stones (struvite)
alkaline pH
infection w/ urease-positive bugs (Proteus, Staph, Klebsiella)
staghorn calculi (nidus for UTIs)
70
uric acid stones
acidic pH
radioLUCENT
from hyperuricemia (gout); seen in dz w/ increased cell turnover like LEUKEMIA
tx = alkalinization of urine
71
cystine stones
acidic pH
HEXAGONAL crystals - of sulfur-containing compounds!
2ndary to cystinuria
tx = alkalinization
72
RCC originates from what cells
PCT cells - clear cells! (filled w/ lipids + carbs)
73
RCC spread =
hematogenously by invading renal vein --> IVC
74
RCC ass w/ what paraneoplastic synd
ectopic EPO
ACTH
PTHrP
prolactin
75
Wilm's tumor (nephroblastoma) contains what cells
embryonic glomerular structures (blastema)
76
acute pyelonephritis histo + casts
neutrophilic infiltrate
| WBC casts
77
chronic pyelonephritis histo + casts
```
lymphocytic infiltration + corticomedullary fibrosis (scarring)
eosinophilic casts (thyroidization of kidney)
```
78
drugs implicated in drug-induced interstital nephritis
1-2 wks after: penicillin derivatives, diuretics, sulfonamides, rifampin
months after: NSAIDS
chronic interstitial nephritis: lithium, cyclosporine
79
diffuse cortical necrosis ass w/?
obstetric complic (ex. placenta abruptio)
septic shock
ARDS
80
acute tubular necrosis features?
- 3 stages (inciting, maintenance, recovery)
- inj + necrosis of tubular epith cells
- ass w/ aminoglycosides, cisplatin, amphotericin B, foscarnet, heavy metals, ethylene glycol, crush injury (myoglobiuria), toxins, renal ischemia (shock, sepsis)
- granular "muddy brown" casts seen****
- w/ drugs/toxins --> PCT suscept; w/ renal ischemia --> PCT + medullary segment of thick ascending limb suscept
81
in ATN, death occurs usually in what phase
inciting
82
maintenance phase of ATN =
oliguria
risk of hyperkalemia
1-3 wks
83
recovery phase of ATN =
polyuria
risk of hypokalemia (bc of high vol + hypotonic urine)
BUN + serum creatinine fall
84
renal papillary necrosis ass w/
DM
acute pyelonephritis + UT obstruction
chronic phenacetin use (ex. acetominophen)
sickle cell anemia/trait
85
prerenal azotemia =
- bc of decreased RBF (ex. hypotension, NSAIDs)
- Na/H2O and urea retained to conserve vol
- INCREASED BUN/creatinine ratio
86
intrinsic renal failure =
- cause = ATN or ischemia/toxins
- patchy necrosis
- epith/granular casts in urine
- DECREASED BUN/creatine ratio
87
postrenal azotemia =
- due to outflow obstuction (stones, BPH, neoplasia, etc.) - forces BUN back into blood
- ONLY w/ bilat obstruction
- INCREASED BUN/creatinine ratio
88
features of uremia
```
pericarditis
N/V
asterixis
encephalopathy
platelet dysfunt (qualitative dysfunct; NORMAL platelet count)
INCREASED BUN/creatinine ratio
```
89
histo in renal osteodystrophy
subperiosteal thinning of bones
90
medullary cystic disease
- AD
- tubulointerstital fibrosis (cysts in medullary CD)
- inability to conc urine
- SHRUNKEN KIDNEYS on US
