Biochemistry

Question 1

what would the ideal marker of GFR do?

Answer 1

appear at a constant rate
freely filtered at the glomerulus
not reabsorbed
not secreted
does not undergo extra-renal elimination

Question 2

example of ideal GFR marker

Answer 2

inulin

Question 3

why is ammonia converted to urea?

Answer 3

it is toxic

Question 4

urea can be used as a GFR marker, but what are it’s limitations?

Answer 4

does not appear at a constant rate
reabsorbed
extra-renal elimination

Question 5

what is creatinine?

Answer 5

waste product of muscle breakdown

Question 6

what factors cause creatinine to vary between people?

Answer 6

age
sex
muscle mass
diet

Question 7

how to collect creatinine as a GFR marker?

Answer 7

24 hour collection

Question 8

limitation of eGFR

Answer 8

not accurate >60ml/min

Question 9

when is eGFR used?

Answer 9

chronic kidney disease/failure classification

Question 10

are plasma proteins normally retained?

Answer 10

yes (should not be excreted into the urine)

Question 11

what is nephrotic syndrome?

Answer 11

too much protein in the urine

Question 12

what is the earliest form of nephrotic syndrome?

Answer 12

microalbuminuria

Question 13

define oligouria

Answer 13

low urine output

Question 14

classification of oligouria

Answer 14

1. pre-renal
2. renal
3. post-renal

Question 15

causes of pre-renal oligouria

Answer 15

reduced renal perfusion

• blood loss
• hypovolaemia

Question 16

causes of renal oligouria

Answer 16

kidney tissue damage

• GM
• nephrotoxins

Question 17

causes of post-renal oligouria

Answer 17

obstructions

• stones
• malignancy

Question 18

what hormones does the kidney produce?

Answer 18

renin
1,25 dihydroxycholecalciferol
erythropoietin

Question 19

what hormones act on the kidney?

Answer 19

1. ADH
2. PTH
3. aldosterone