Urology and Nephrology Intro

Question 1

What is Azotemia?

Answer 1

Abnormal increase in concentration of nitrogenous wastes in blood.

Question 2

What are some pre-renal causes of azotemia?

Answer 2

perfusion

• dehydration
• hypoadrenocorticism
• cardiac disease
• shock
• hypovolemia

Question 3

What are some renal causes of azotemia?

Answer 3

parenchymal disease

• infectious cysts
• Inflammation
• Neoplasia
• toxins

Question 4

What are some post-renal causes of azotemia?

Answer 4

obstructive

- blockage - ureteral/bladder or urethral

Question 5

What is renal failure?

Answer 5

clinical syndrome that occurs when kidneys are no longer able to maintain:
- regulatory function
- excretory function
- endocrine function
retention of nitrogenous solutes and derangements of fluid, electrolytes and acid-base balance

Question 6

Renal failure occurs when how much of the nephron population is non-functional?

Answer 6

> 75%

Question 7

What is renal disease?

Answer 7

presence of morphological or functional lesions in one or both kidneys, regardless of extent

Question 8

What is uremia?

Answer 8

constellation of clinical signs and biochemical abnormalities associated with critical loss of functional nephrons.
Includes extra-renal manifestations of renal failure (eg: uremic gastropathy, hyperparathyroidism)

Question 9

What are some techniques used to test glomerular function?

Answer 9

Accurate
- clearance of radioisotopes with renal scintigraphy
- Iohexal/inulin/creatinine clearance tests
Indirect
- serum urea levels
- serum creatinine levels
- cystatin C 
- SDMA - symmetrical dimethylarginine

Question 10

What is the gold standard test for glomerular function?

Answer 10

clearance of radioisotopes with renal scintigraphy

Question 11

What happens if concentration of urea in the renal medulla get too low?

Answer 11

doesn’t maintain solute gradient -> medullary washout

Question 12

True or False? Urea Clearance is a reliable estimate of GFR.

Answer 12

False

Question 13

What are the indirect methods for estimating glomerular function?

Answer 13

• serum urea levels
• serum creatinine levels
• cystatin C
• SDMA (symmetrical dimethylarginine)

Question 14

True or False? The relationship between creatinine and GFR is linear.

Answer 14

False

Question 15

What does GFR have to decrease to for azotemia to develop

Answer 15

GFR has to drop to 25%

Question 16

True or False? Creatinine level cannot prognosticate on the magnitude of azotemia.

Answer 16

True

Question 17

What is cystatin C produced by?

Answer 17

all cells with a nucleus.

Question 18

True or False? Cystatin C is not reabsorbed by the proximal tubular cells.

Answer 18

False. it is almost completely reabsorbed by the proximal tubular cells and catabolized to it’s constituent amino acids.

Question 19

What is SDMA (Symmetric Dimethylarginine)?

Answer 19

a methylated form of the amino acid arginine, which is produced in every cell and relayed around the bodies circulation during protein synthesis.