100% Verified
What is the mutation in AD PKD? Correct Ans-APKD1 or APKD2 genes (adult polycystic
kidney disease) [APKD1 is most common and is present in ~85% of cases]
Why does AD PKD present in adulthood? Correct Ans-Cysts develop over time
What is a common cause of death in those with AD PKD Correct Ans-Berry aneurysm -->
Occurs in the circle of willis
What three things is AD PKD associated with? Correct Ans-Berry aneurysm, hepatic cysts,
mitral valve prolapse
Inherited AD defect leading to cysts in medullary collecting ducts of kidney Correct Ans-
Medullary cystic kidney disease
What does parenchymal fibrosis of medullary cystic kidney disease cause? Correct Ans-
Shrunken kidneys and worsening renal failure
Kidneys in PKD vs. medullary cystic kidney disease Correct Ans-PKD: enlarged
Medullary cystic kidney disease: shrunken
, Pathoma: Chapter 12 Test Questions with Solutions
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Acute, severe decrease in renal function that develops in days Correct Ans-Acute renal
failure
What is the hallmark of acute renal failure? Correct Ans-Azotemia (increased BUN and
creatinine) often with oliguria
What is azotemia and how is it measured? Correct Ans-Increase in nitrogenous waste
products in the blood; measured with blood BUN and Cr concentrations
What are the three categories of acute renal failure based on etiology? Correct Ans-Pre-
renal, post-renal, intrarenal azotemia
What causes prerenal azotemia (ARF)? Correct Ans-Decreased blood flow to the kidneys
(i.e. cardiac failure); common cause of ARF
How does prerenal azotemia affect GFR and other parameters? Correct Ans-Decrases GFR;
azotemia and oliguria
What is BUN:Cr in prerenal azotemia and why? Correct Ans-Over 15. RAAT activated
because not enough blood is getting to kidney; this causes aldosterone to be released, which
causes Na/H2O to be resorbed. BUN follows, but Cr can't, raising ratio
, Pathoma: Chapter 12 Test Questions with Solutions
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Tubular function in prerenal azotemia, and how does it effect FeNa and osmolality of urine?
Correct Ans-Tubular function is intact, so fractional excretion of Na is less than 1% and
osmolality is over 500 mOsm/kg (can concentrate)
What causes postrenal azotemia? Correct Ans-Obstruction of urinary tract downstream
from kidney (ureters)
How does postrenal azotemia affect GFR and other parameters? Correct Ans-Decreases
GFR, causes azotemia and oliguria
BUN:Cr, tubular function in early stages of postrenal azotemia Correct Ans-BUN:Cr over 15
(tubular function is intact)
Tubular function intact (FeNa < 1% and urine osmolality over 500 mOsm/kg)
BUN:Cr, tubular function in late stages of postrenal azotemia Correct Ans-BUN:Cr < 15
(because BUN reabsorption relies on intact tubule)
Tubular function not intact, so FeNa increases above 2% and urine osmolality is less than 500
mOsm/kg (can't concentrate urine)
What is the most common cause of acute renal failure? Correct Ans-Acute tubular
necrosis, which is a cause of intrarenal azotemia
Acute tubular necrosis definition Correct Ans-Injury and necrosis of tubular epithelial cells
, Pathoma: Chapter 12 Test Questions with Solutions
100% Verified
GFR in acute tubular necrosis (intrarenal azotemia) and why? Correct Ans-GFR decreases
because necrotic cells plug tubules, creating a back pressure into the glomerulus and
decreasing GFR
Disease with brown, granular casts seen in the urine Correct Ans-Acute tubular necrosis
(intrarenal acute azotemia); Circled in picture = granular casts that are seen in urine
What is seen in urine in acute tubular necrosis? Correct Ans-Brown, granular casts in urine
(dead epithelial cells)
What is the status of tubular epithelium in acute tubular necrosis as a cause of intrarenal
azotemia? Correct Ans-Tubular epithelium not intact; BUN:Cr less than 15, FeNa over 2%,
and urine osmolality < 500 mOsm/kg
What are the two possible etiologies of acute tubular necrosis? Correct Ans-1. Ischemic
2. Nephrotoxic
How does ischemia cause acute tubular necrosis, and what often precedes it? Correct Ans-
Decreased blood supply results in necrosis of tubules; often preceded by prerenal azotemia
What are the two areas of the kidney that are particularly susceptible to ischemic damage?
Correct Ans-Proximal tubule and medullary segment of the thick ascending limb