Biochemical Measurements

Question 1

What takes place in PCT?

Answer 1

reabsorption

Question 2

What takes place in loop of Henle?

Answer 2

concentration of the medulla

Question 3

What takes placei n the DCT?

Answer 3

secretion and reabsorption (fine-tuning)

Question 4

What takes place in the collecting duct?

Answer 4

water reabsorption

Question 5

What is the gold standard for measuring GFR?

Answer 5

inulin

Question 6

What are the problems iwth inulin?

Answer 6

exogenous and not easy to measure

Question 7

What organ produces urea from ammonia?

Answer 7

liver

Question 8

How much creatinine is secreted by the distal tubule?

Answer 8

5-10%

Question 9

What is the problem with creatinine??

Answer 9

above 60ml/min there is little change in creatinine despite steep fall in GFR

Question 10

What are the confounders for serum creatinine?

Answer 10

age; sex; muscle mass and diet

Question 11

What is clearance?

Answer 11

the volume of plasma cleared of a substance perminute

Question 12

What is equation for the clearance of a substance?

Answer 12

conc. of X in urine x Vu/ plasma conc. of X

Question 13

Whati s the Cock-croft-Gault method used for?

Answer 13

used to calculate drug dosages

Question 14

What type of clearnace of creatinine is most sensitive?

Answer 14

urine creatinine is better than serum creatinine

Question 15

What amount of protein per day indicates significant glomerular damage?

Answer 15

> 150mg/day

Question 16

Why is protein/creatinine ratio spot sample better than just measuring protein?

Answer 16

urine may be dilute or concentration so comparing to creatinine adjusts for that

Question 17

What is a normal PCR?

Answer 17

<15mg/mmol

Question 18

Whati s the earliset expression of diabetic nephropathy?

Answer 18

microalbuminuria

Question 19

What does microalbuminuria refer to?

Answer 19

excretion of albumin in abnormal quantities but isn’t picked up by dipstick

Question 20

What drug is given to treat microalbuminuria?

Answer 20

ACEi

Question 21

What gives an indication of how the tubules are working?

Answer 21

urine/serum osmolality

Question 22

What does a urine/serum osmolality of 1 indicate?

Answer 22

that the tubules aren’t working as there has been no reabsorption of water and so there must be intrisnic renal damage

Question 23

What are the two main causes of proteinuria?

Answer 23

overflow- too much protein and glomerular- where the glomerulus is leaky

Question 24

What is the commonest cause of proteinuria?

Answer 24

glomerular

Question 25

What is an example of overflow proteinuria?

Answer 25

multiple myeloma