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Water in the Blood

The volume of urine produced depends on the internal conditions. The volume of water in the blood is monitored by the brain. This is how the body responds to having too much or too little water in the blood:

Too little water

Too little water

  • The brain triggers the release of anti-diuretic hormone (ADH).
  • This increases the permeability (ability of things to pass through) of the collecting duct. This means that more water is reabsorbed back into the bloodstream.
  • This results in a small volume of concentrated urine.
Too much water

Too much water

  • The brain signals to stop the release of anti-diuretic hormone (ADH).
  • This reduces the permeability of the collecting duct. This means that less water is reabsorbed back into the bloodstream.
  • This results in a large volume of dilute urine.
Jump to other topics
1

The Nature & Variety of Living Organisms

2

Structure & Functions in Living Organisms

3

Organism Functions

3.1

Respiration

3.2

Gas Exchange

3.3

Transport

3.4

Excretion

3.5

Coordination & Response

4

Reproduction & Inheritance

5

Ecology

6

Biological Resources

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