Diuretics 1

Question 1

total body fluids account for what % of the body weight?

Answer 1

60% (for 70kg person it’s about 42L)

Question 2

ICF is about what % of the body weight?

Answer 2

40% = 28L

Question 3

ECF is about what % of body weight?

Answer 3

20% = 14L

Question 4

blood pressure is

Answer 4

TPR X CO

Question 5

cardiac output is

Answer 5

HR X SV

Question 6

what is edema?

Answer 6

excess accumulation of fluid in the interstitial space due to cardiac, renal, hepatic or endocrine dysfunction (hyperaldosteronism)

Question 7

Decreased circulating volume decreases renal perfusion pressure and activates

Answer 7

the reninangiotensin-aldosterone system, which further increases sodium retention and maintains the edema.

Question 8

Edematous disease states include

Answer 8

1. congestive heart failure (↑ hydrostatic pressure),
2. liver disease (↓ oncotic pressure),
3. nephrotic syndrome (↓ oncotic pressure) and
4. pulmonary edema (↑ hydrostatic pressure).

Question 9

How is diuretics help remove the edema?

Answer 9

1. Diuretics decrease plasma volume by “forcing” increased elimination of sodium and water in the urine.
2. This decreases hydrostatic pressure and increases oncotic pressure, which favors absorption of edematous fluid in the interstitial space back into the intravascular
   space, correcting the edema.

Question 10

what happens with Na in the proximal tubule?

Answer 10

Approximately 66% of the filtered sodium (16,500 mEq/day) and most of the filtered bicarbonate is reabsorbed in the proximal tubule. Most of the filtered nutritive solutes (glucose, etc) are reabsorbed in the proximal tubule and returned to the circulation in the
renal vein.