Renal Flashcards Preview

Step 1 Flash Cards > Renal > Flashcards

Flashcards in Renal Deck (67):
1

most common site of obstruction in fetus

ureteropelvic junction

2

multicystic dysplastic kidney

due to abnormal interaction between ureteric bud and metanephric mesenchyme
- non functional kidney of cysts and connective tissue

3

glomerular filtration barrier

- fenestrated capillaries provide size barrier
- BM provides charge membrane (lost in nephrotic syndrome)
- epithelial layer has podocytes

4

equations for GFR, RPF and FF

GFR = Cinulin = Ui x V/Pi
RPF = RBF x (1-Hct)
FF = GFR / RPF = GFR / (RBFx(1-Hct))

5

Hartnup disease

deficiency in neutral AA transporter, leading to dec tryptophan uptake
- can lead to pellagra-like symptoms because niacin is derived from tryptophan
- treat with high protein diet and nicotinic acid

6

early proximal convoluted tubule functions

- reabsorb AA, glucose, and most H2O, Na, Cl, Phos, K
- secretes NH3 (buffers H+)
- PTH inhibits Na/phos transport, inc phos excretion
- ATII increases Na/H exchange, inc Na, H2O and HCO2- absorption (permitting contraction alkalosis)
- 65-80% of Na reabsorbed

7

thin descending loop of henle

- water passively reabsorbed due to concentration gradient

8

thick ascending loop of henle

- actively reabsorbs Na, K and Cl through Na/K/2Cl transporter
- Mg and Ca reabsorbed paracellularly 2/2 K backleak
- impermeable to H2O
- 10-20% of Na reabsorbed

9

early distal convoluted tubule

- actively reabsorbs Na, Cl
- PTH inc Ca/Na exchange, inc Ca reabsorption
- 5-10% of Na reabsorbed

10

collecting tubule

reabsorbs Na in exchange for K+ and H+ (mediated by aldosterone)
- ADH acts on V2 receptor and inc insertion of aquaporins
- 3-5% of Na reabsorbed

11

Fanconi syndrome

- reabsorptive defect in the PCT
- inc excretion of AA, glucose, HCO3- and phos
- may result in metabolic acidosis
- causes include hereditary defects (Wilson disease), ischemia and nephrotoxins/drugs

12

Bartter syndrome

- reabsorptive defect in the thick ascending loop of Henle
- AR, affects Ka/K/2Cl transporter
- hypokalemia and metabolic alkalosis, hypercalciuria

13

Gitelman syndrome

- reabsorptive defect of NaCl in DCT
- AR
- hypokalemia and metabolic alkalosis
- NO hypercalciuria

14

Liddle syndrome

- inc Na reabsorption in distal and collecting tubules
- AD
- results in hypertension, hypo K, metabolic alkalosis, low aldo
- treat with amiloride

15

effects of Angiotensin II

- acts on AT I receptors on vascular smooth muscle to constrict
- constricts efferent arteriole to inc FF despite low volume state (compensatory Na reabsorption)
- stimulates aldo (inc Na reabsorption)
- stimulates ADH (inc H2O reabsorption)
- stimulates prox tubule Na/H activity
- stimulates hypothalamus (thirst)

16

juxtaglomerular apparatus function and B-blockers effect on it

- JG cells (modified smooth muscle cells) sense dec renal blood flow and release renin
- macula densa senses NaCl in the distal convoluted tubule --> renin
- B1 sympathetic tone also increases renin release
- b blockers block the B1 receptors on JGA, causing decreased renin release

17

Vit D in the kidney

proximal tubule cells convert 25-OH vit D to 1,-25 OH2 vit D via 1-alpha hydroxylase
- this enzyme is stimulated by PTH

18

NSAIDs

- block the protective vasodilation of the afferent arteriole that usually would increase RBF
- can constrict the afferent arteriole and dec RBF so much they cause acute renal failure

19

Winter's formula

PCO2 = 1.5[HCO3-] + 8 +/- 2

20

causes of anion gap metabolic acidosis

MUDPILES
-methanol, uremia, DKA, propylene glycol, iron tablets or INH, lactic acidosis, ethylene glycol, salicylates

21

causes of non-anion gap metabolic acidosis

HARD ASS
- hyperalimentation, addisons, RTA, diarrhea, acetazolamide, spironolactone, saline infusion

22

metabolic alkalosis with low urine Cl

- vomiting, NG aspiration, prior diuretic use

23

metabolic alkalosis with high urine Cl and hypo/euvolemia

- diuretic use, Barter and Gittelman syndromes

24

metabolic alkalosis with high urine Cl and hypervolemia

excess mineralocorticoids (primary hyperaldo, cushing disease, ectopic ACTH prodcuction)

25

renal tubular acidosis

d/o of the renal tubules which leads to a non-anion gap hyperchloremic metabolic acidosis

26

RTA 1

- pH > 5.5
- defect in alpha intercalated cell's ability to secrete H+ (no new HCO3- is generated)
-associated with hypokalemia and inc risk for calcium phosphate stones
- causes: amphotericin B, analgesic nephropathy, MM, congenital urinary anomalies

27

RTA 2

- pH < 5.5
- defect in prox tubule HCO3- reabsorption
- associated with hypoK, inc risk for hypophosphatemic rickets
- causes: Fanconi syndrome, chemicals toxic to prox tubules (lead, aminoglycosides), and carbonic anhydrase inhibitors

28

RTA 4

- pH < 5.5
- hypoaldo, aldo resistance or K sparing diuretics
- hyperkalemia impairs ammoniagenesis, dec H+ excretion into the urine

29

RBC casts mean

glomerulonephritis, ischemia or malignant hypertension

30

WBC casts mean

tubulointerstitial inflammation, acute pyelo, transplant rejection

31

fatty casts ("oval fat bodies") mean

nephrotic syndrome

32

granular ("muddy brown") casts mean

acute tubular necrosis

33

waxy casts mean

advanced renal disease/chronic renal failure

34

hyaline casts mean

nonspecific, can be norm esp in concentrated urine

35

eosinophilic casts mean

MM, chronic pyelo

36

nephritic syndromes

inflammatory process leading to hematuria and RBC casts in the urine
-assoc with azotemia, oliguria, HTN and proteinuria (< 3.5mg/day)
- acute poststrep glomerulonephritis, RPGN, IgA nephropathy, Alport syndrome

37

nephtitic/nephrotic syndromes

-diffuse proliferative glomerulonephritis, membranoproliferative glomerulonephritis

38

nephrotic syndromes

- > 3.5 mg protein/day, hyperlipidemia, fatty casts, edema, hypercoaguability
- FSGS, Membranous nephropathy, MCD, amyloidosis, diabetic glomerulonephropathy

39

FSGS

LM - segmental sclerosis and hyalinosis
IF -ve
EM - effacement of foot process
- most common cause of nephrotic syndrome in hispanics and AA
- idiopathic or 2/2 HIV, sickle cell, heroin, obesity, interferon treatment, CKD
- inconsistent response to steroids

40

membranous nephropathy microscope findings

LM - diffuse capillary and GBM thickening
IF - granular as a result of immune complex deposition. nephrotic presentation of SLE
EM - "spike and dome" appearance with subendothelial deposits

41

membranous nephropathy epi/cause

- most common cause of nephrotic syndrome in caucasian adults
- can be due to Ab to phospholipase A2 receptor, drugs (NSAIDS), HBV/HCV, SLE or solid tumors
- poor response to steroids

42

MCD

LM normal, neg IF, EM - effacement of foot processes
- most common in kids
- triggered by recent infection, immunization, Hodgkins Lymphoma
- excellent response to steroids

43

amyloidosis

- LM - congo red stain shows apple-green birefringence under polarized light
- associate with chronic conditions (TB, MM, rheumatoid arthritis)

44

Type I MPGN

- subendothelial immune complex deposits with granular IF, "tram-track" appearance due to GBM splitting
- nephritic/nephrotic syndrome
- assoc with HBV, HCV

45

Type II MPGN

- inramembranous IC deposits, "dense deposits"
- assoc with C3 nephritic factor (stabilizes C3 convertase --> serum C3 levels)

46

diabetic glomerulonephropathy

LM - mesangial expansion, GBM thickening, eosinophilic nodular glomerulosclerosis
- glycosylation of GBM -- inc permeability and thickening
- glycosylation of efferent arterioles inc GFR, leads to mesangial expansion

47

acute poststreptococcal glomerulonephritis

- LM - glomeruli enlarged and hypercellular
- IF - "starry sky" granular appearance and "lumpy bumpy" due to IgG, IgM and C3 deposition along GBM and mesangium
- EM - immune complex humps
- 2 weeks after GAS pharyngitis or skin infection
- Type III HS reaction that resolves spontaneously
- coca-cola urine, ASO titer and low C3

48

rapidly progressive (crescentic) glomerulonephritis

- LM and IF - crescent moon shape (crescents consist of fibrin and plasma proteins with glomerular parietal cells, monocytes and macrophages)
- 2/2 Goodpasture's disease, Wegener's, Microscopic polyangiitis
- poor prognosis

49

diffuse proliferative glomerulonephritis

- due to SLE or MPGN
- LM - "wire looping" of capillaries
- EM - subendothelial and sometimes intramembranous IgG-based ICs often with C3 deposition
- IF - granular
- most common cause of death from SLE

50

IgA nephropathy (Berger disease)

- LM - mesangial proliferation
- EM - mesangial IC deposits
- IF - IgA based IC deposits in the mesangium
Seen with HSP.
- often presents with a URI or acute gastroenteritis ("a few days after a flu-like illness")

51

alport syndrome

- mutation of type IV collagen -- thinning and splitting of the glomerular basement membrane. most commonly x linked

52

calcium oxalate kidney stones

- radioopque and envelope/dumbbell shaped
- promoted by hypercalciuria
- can result from ethylene glycol, vit C abuse, crohns
- treat with thiazides and citrate (prevents precipitation)

53

ammonium magnesium phosphate kidney stones

- radioopaque and coffin lid shaped
- caused by infection by urease + bugs, because they alkalinize the urine
- treat infection, remove stones

54

uric acid stones

- radiolucent, rhomboid or rosettes
- risk factors include decreased urine volume, arid climates and acidic pH
- can be 2/2 gout or high cell turnover states (leukemia)
- treat by alkalinizing urine

55

cystine stones

radioopaque and hexagonal
- sodium nitroprusside test +
- treat by alkalinizing the urine and hydrating

56

renal cell carcinoma

-originates from the proximal tubule cells --> polygonal clear cells filled with accumulated lipids and carbs
- hematuria, palpable mass, polycythemia, flank pain, fever, weight loss
- invades renal vein/IVC and spreads hematogenously
- golden yellow on macroscopic exam
- resection and immunotherapy, resistant to chemo

57

renal oncocytoma

- benign epithelial cell tumor, well circumscibed with central scar
- large eosinphilic cells with abundant mitochondria without perinuclear clearing
- painless hematuria, flank pain, abdominal mass

58

Wilms tumor

- most common renal malignancy in kids (2-4)
- large palpable flank mass and/or hematuria
- "loss of function" mutations to tumor suppressor genes WT1 or WT2
- assoc with VHL or WAGR complex (Wilms tumor, Aniridia, GU malformations, Retardation)

59

Transitional Cell Carcinoma

- painless hematuria with no casts
- associated with problems with your Pee SAC: phenacetin, smoking, aniline dyes, and Cyclophosphamide

60

squamous cell carcinoma of the bladder

- due to chronic iritation of the bladder --> squamous metaplasia and dysplasia
- schistosomiasis, chronic cystitis, smoking, chronic nephrolithiasis
- presents with painless hematuria

61

acute infectious cystitis

- causes: E. coli, s. saprophyticus (sexually active women), Klebs, Proteus, adenovirus (hemorrhagic cystitis)
- sterile pyuria and neg urine cultures seen with gonorrhea and chlamydia

62

acute pyelo

- WBC casts in the urine
- complications include chronic pyelo, renal papillary necrosis, and perinephric abscess

63

chronic pyelo

coarse asymmetric corticomedullary scarring, blunted calyx
- tubules contain eosinophilic casts resembling thyroid tissue (thyroidization of the kidney)

64

ATN phases

- inciting event
- maintenance phase - oliguric, lasts 1-3 weeks with risk of hyperkalemia, met acidosis, volume overload, inc creat and BUN
- recovery phase - polyuric, BUN and Cr fall, risk of hypoK, hypoMg, hypoPhos, hypoCa
- can be ischemic (prox tubule/thick ascending limnb) or nephrotoxic (prox tubule)

65

renal papillary necrosis

- sloughing of renal papillae - gross hematuria and proteinuria
- assoc with DM, acute pyelo, chronic phenacetin use, sickle cell

66

prerenal/renal/postrenal

urine osmolarity - > 500, >40, >40
FeNa - 2%, >1-2%
BUN/Cr - >20, 15

67

consequences of renal failure

MAD HUNGER
- Metabolic Acidosis, Dyslipidemia, Hyperkalemia, Uremia, Na/H2O retention, Growth retard/DD in kids, EPO failure, Renal osteodystrophy
- can't excrete phos or reabsorp Ca --> low Phos, High Ca, inc PTH, subperiosteal thinning of bones