Questions: Multiple Choice Question In response to increased osmotic pressure, the pituitary gland releases which signals the kidneys to retain water, thus reducing urine output. O angiotensin O antidiuretic hormone O renin O aldosterone Need help? Review these concept resources.

The answer is the second one: antidiuretic hormone.

Explanation for each option:

1. Angiotensin: This is part of the renin-angiotensin system and primarily helps regulate blood pressure and fluid balance. It does not directly signal the kidneys to retain water in response to increased osmotic pressure.

2. Antidiuretic hormone (ADH): This hormone, also known as vasopressin, is released by the pituitary gland in response to increased osmotic pressure. It signals the kidneys to retain water, thus reducing urine output. This is the correct answer.

3. Renin: This enzyme is released by the kidneys and plays a role in the renin-angiotensin system, which helps regulate blood pressure. It does not directly cause the kidneys to retain water in response to osmotic pressure.

4. Aldosterone: This hormone is involved in the regulation of sodium and potassium levels and helps control blood pressure. It promotes sodium retention and potassium excretion by the kidneys but is not directly responsible for water retention in response to osmotic pressure.

In summary, the antidiuretic hormone is the correct answer as it directly influences the kidneys to retain water in response to increased osmotic pressure.