Sodium and Water Balance

Question 1

primary hormone controlling water balance?

Answer 1

ADH

Question 2

where is ADH released from?

Answer 2

posterior pituitary

Question 3

how does ADH basically control water balance?

Answer 3

causes water to be reabsorbed from the renal tubules meaning you pee less and loose less water

Question 4

how is urine concentration/dilution measured?

Answer 4

osmolality
concentrated urine = high osmolality
dilute urine = low osmolality

Question 5

how does ADH cause water reabsorption?

Answer 5

countercurrent multiplication

Question 6

what is countercurrent multiplication?

Answer 6

process occurring in loop of henle of juxtamedullary nephrons which uses energy to generate an osmotic gradient that enables you to reabsorb water from the tubular fluid

Question 7

what mainly controls sodium balance?

Answer 7

steroids (from adrenals)

effect of steroids on Na+ balance known as mineralocorticoid activity

Question 8

what do steroids do to control sodium balance?

Answer 8

cause sodium reabsorption in exchange for potassium and H+

too much mineralocorticoid activity = sodium gain, too little mineralocorticoid activity = sodium loss

Question 9

examples of steroids with mineralocorticoid activity?

Answer 9

aldosterone (mainly)

others such as cortisol