9.4 + 9.5

Question 1

How much of body fluid is intra vs extracellular?

Answer 1

Inter: two thirds
Extra: one third

Question 2

Break down the percentages within extracellular fluid

Answer 2

80% interstitial
20% Plasma

Question 3

How is water lost from the body (most least)?

Answer 3

• Kidneys
• Skin
• Lungs
• GI tract

Question 4

How is water gained by the body (most/least)?

Answer 4

• Ingested liquids
• Ingested foods
• Metabolic water

Question 5

How is bodily water loss regulated?

Answer 5

• Follows movements of ions such as sodium into plasma, leading to excretion

Question 6

Describe alkalosis

Answer 6

• pH of the body becomes too high
• Overexcites the CNS
• Convulsions/death

Question 7

Describe acidosis

Answer 7

• pH of the body becomes too low
• Depresses the CNS
• Coma

Question 8

Loop diuretics mech

Answer 8

Inhibit Na+/K+/2Cl- transporter, causing these ions to be retained in the filtrate and thus increasing urine excretion

Question 9

Thiazide diuretics mech

Answer 9

Inhibit Na+/K+/2Cl- cotransporter in DCT, causing ion retention and increased volume of urine

Question 10

Which have stronger effects: loop diuretics or thiazides? Therefore, which is prescribed for milder oedematous states?

Answer 10

• Thiazide is weaker
• Prescribed when oedematous state is weaker

Question 11

Mineralocorticoid antagonist mech

Answer 11

Increase retention of K+ in EC space and Na+ in urine, increasing urine volume and increasing volume of urine

Question 12

Potassium sparing diuretics mech

Answer 12

Inhibit Na/K pumps in distal nephron, causing retention of sodium in filtrate and thus increased urine output