Nephrology

Question 1

In which section of the nephron is the tubular fluid isosmotic to the plasma?

1. Proximal tubule
2. Descending loop of Henle
3. Distal tubule
4. Collecting tubule

Answer 1

1. Proximal tubule

Descending loop of Henle: 1060
Distal tubule: 1001
Collecting tubule: 1035

Question 2

What should be considered regarding the use of antimicrobials for the treatment of canine chronic prostatitis?

1. Antimicrobials should be used for 2 weeks maximum.
2. Antimicrobials should have a low pKa.
3. Antimicrobials should have high protein binding.
4. Antimicrobials should have low lipid solubility

Answer 2

2. Antimicrobials should have a low pKa

ab for 4-6weeks, and to pass the prostatic barrier: low protein binding and high lipid solubility

Question 3

Which of the following calculi are less visible on radiographs?

1) struvite
2) Ca oxalate
3) Urate
4) cysteine

Answer 3

3) Urate calculi can be radiolucent.

Struvite and CA ox are well opaque.

Cysteine can be either though most commonly opaque

Question 4

Which of the following is a disease of the proximal tubule mostly?

1) Hyperuricosuria
2) Fanconi syndrome /Basenji
3) Renal tubular acidosis type A
4) Cystinuria

Answer 4

2) Fanconi syndrome. Altered reabsorption through the proximal tubule
3) renal tubular acidosis type A is mostly lack of H+ secretion in the distal tubule

Question 5

How much of Na+ is reabsorbed in the proximal tubule?

1) 45%
2) 30%
3) 65%
4) 50%

Answer 5

3) 65% of Na+ is reabsorbed in the PCT. Same amount of water.

Roughly 50-55% of K and Cl.
Roughly 100% of glucose, amminoacid
Roughly 90% of HCO3 -

Question 6

What is the role of the macula densa cells?

1) detect changes in blood pressure
2) detect changes in CO2 levels
3) detect changes in HCO3- levels
4) detect changes in Na+ Cl - levels

Answer 6

4) Macula densa cells responds to increased concentration of solutes (Na Cl) in the distal tubule. They both enter the cell with a simport and the Na+ stimulate the synthesis of ATP and Adenosine is released in the blood. This activates the mesangial cells that release calcium
- -> to the Juxtaglomerular cells –> Renin release

–> to the smooth muscle cells of the arterioles –> contraction

Question 7

What are the intrinsic mechanism of autoregulation of GFR in the kidneys?

1) activation of the sympathetic nervous system
2) myogenic response
3) tubuloglomerular feedback
4) release of Epinephrine

Answer 7

2) and 3).

1) is a systemic mechanism of regulation and 4) is associated with 1).

Question 8

Which breeds are predisposed to membrano-proliferative glomerulopathy?

1) Labrador
2) Newfoundland
3) Golden retriever
4) German shepherd

Answer 8

1) and 3)

Newfie are predisposed to Cystinuria (with labradors and Bull terrier).

Question 9

Where do NSAIDs act in the kidney to cause their known side effects?

1) proximal tubule
2) efferent arterioles
3) afferent arterioles
4) glomerularr podocytes

Answer 9

3) afferent arterioles. They cause vasoconstriction leading to hypoperfusion

ACEi and ARB act on the efferent arterioles.