Question

Short / Long answer type questions.
If you drank a liter of water, what effect would this have on the osmotic pressure of your blood and how would the level of ADH change in your blood?

Answer 1

Drinking a litre of water will increase fluid volume in the body. This will result in dilution of blood and decrease in osmotic pressure of blood. Osmoreceptors in hypothalamus will detect this change and release of ADH will be suppressed. This will eventually lead to a decreased level of ADH in blood. ADH is concerned with reabsorption of water from renal tubule, so it is actually needed when there is a need for water retention. In case of sufficient availability of water, ADH is not required hence its release is suppressed.