ANP 1107A Renal Lecture 3 March 8

Question 1

What does ADH do to the collecting duct?

Answer 1

it acts at collecting ducts to increase number of water channels in principal cells

Question 2

collecting ducts extend into

Answer 2

medullary area

• filtrate can again attain an osmolarity up to 1200 mOsm

Question 3

what is facultative water reabsorption?

Answer 3

Water reabsorption that depends on the pressence of ADH. In the presence of ADH 99% of H20 in filtrate is reabsorbed.

Question 4

what does it mean when levels of ADH are too low?

Answer 4

means that the kidneys are allowing more water to be excreted, which can lead to dehydration.

Question 5

what happens when plasma osmolarity is above 300 mOsm?

Answer 5

increased levels of ADH to conserve body

• high levels of plasma osmolarity = conserve water to maintain a proper balance of fluids and electrolytes in the body

Question 6

for example, what happens when plasma osmolarity is above 300 mOsm?

Answer 6

this happens when you’re sweating or not drinking enough water, it will trigger an increase in ADH to prevent dehydration.

Question 7

What is a diuretic?

Answer 7

is any substance that is not reabsorbed

exceeds renal reabsorption: eg. someone with type 1 diabetes

Question 8

what do caffeine and most prescribed diuretic drugs do?

Answer 8

inhibit Na+ reabsorption

Question 9

what is the net effect of inhibiting Na+ reabsorption

Answer 9

haven’t pulled back as much Na

Question 10

what is the renal clearance calculation

Answer 10

RC = UV/P

Question 11

what is the U

Answer 11

substance mg/ml in urine

Question 12

what is the V

Answer 12

flow rate of urine formation (ml/min)

Question 13

what is the P

Answer 13

substance (mg/ml) in plasma

Question 14

what is the colour/transparency of urine

Answer 14

clear/pale to deep yellow

Question 15

what is urochrome

Answer 15

pigment from heme degradation

Question 16

what does deepness of yellow indicate in urine?

Answer 16

not drinking enough water

-some drugs/vitamins can alter colour of urine

Question 17

what can cloudiness in urine indicate?

Answer 17

bacteria infection

Question 18

where does the odour of urine come from?

Answer 18

will develop ammonia odour if left to stand due to bacterial metabolism of urea

• drugs and vitamins can alter odour

Question 19

pH of urine is usually?

Answer 19

6

but can vary ~4.5-~8)

Question 20

what is acidic urine?

Answer 20

diet rich in protein and whole wheat

Question 21

what is alkaline urine?

Answer 21

diet rich in vegetables

Question 22

what is the chemical composition of urine?

Answer 22

95% water, 5% solutes