Questions: A patient is admitted with severe dehydration and hypotension. Which hormone, when delivered, increases water reabsorption? Oxytocin Vasopressin Luteinizing hormone Adrenocorticotropic hormone

The answer is the second one: Vasopressin.

Explanation for each option:

1. Oxytocin: This hormone is primarily involved in childbirth and lactation. It stimulates uterine contractions during labor and milk ejection during breastfeeding. It does not play a role in water reabsorption or managing dehydration.

2. Vasopressin: Also known as antidiuretic hormone (ADH), vasopressin is responsible for increasing water reabsorption in the kidneys. It acts on the kidney's collecting ducts to promote water retention, which helps to increase blood volume and pressure, making it the correct choice for treating severe dehydration and hypotension.

3. Luteinizing hormone: This hormone is involved in regulating the reproductive system. In females, it triggers ovulation and the development of the corpus luteum. In males, it stimulates testosterone production. It does not affect water reabsorption.

4. Adrenocorticotropic hormone (ACTH): This hormone stimulates the adrenal glands to release cortisol, which is involved in stress response, metabolism, and immune function. It does not directly influence water reabsorption in the kidneys.

In summary, vasopressin is the hormone that increases water reabsorption, making it the appropriate choice for addressing severe dehydration and hypotension.