Water Regulation In The Body

Question 1

How much water does body gain a day by ingestion and metabolic reactions?

Answer 1

About 2500mL

Question 2

How much is ingested liquid?

Answer 2

1600mL

Question 3

How much is moist food?

Answer 3

700mL

Question 4

How much is metabolic reactions?

Answer 4

200mL

Question 5

About how much water is lost daily?

Answer 5

2500mL

Question 6

How much do the kidneys excrete?

Answer 6

1500mL

Question 7

How much evaporates from the skin surface?

Answer 7

600mL

Question 8

Lungs exhale about how much water vapor?

Answer 8

300mL

Question 9

How much is eliminated in feces?

Answer 9

100mL

Question 10

What area in the hypothalamus governs the urge to drink?

Answer 10

Thirst center

Question 11

At what percentage of water loss does mild dehydration begin?

Answer 11

2%

Question 12

What hormone stimulates the thirst center?

Answer 12

Angiotensin II

Question 13

What is the main factor that determines body fluid volume?

Answer 13

The extent of urinary salt loss

Question 14

What happens after a salty meal?

Answer 14

Increased blood volume causes the atria to to release ANP.
ANP promotes decreased blood volume.
Increased blood volume slows renin.
Less angiotensin II means less reabsorption of sodium, chloride, and water.
Less angiotensin means less aldosterone which means slowed reabsorption in the tubules.

Question 15

What is the major hormone that regulates water loss?

Answer 15

Antidiuretic Hormone

Question 16

What do changes in osmotic pressure most often result from?

Answer 16

Changes in sodium