The reabsorption of water in the kidneys is under the control of a hormone
(a) STH
(b) ACTH
(c) LH
(d) ADH

Options

A. STH
B. ACTH
C. LH
D. ADH

Answer

To solve the question regarding which hormone controls the reabsorption of water in the kidneys, we will analyze each option provided:

1. **Understanding the Question**: The question asks which hormone is responsible for the reabsorption of water in the kidneys.

2. **Analyzing Option (a) STH**:
- STH stands for Somatotropic Hormone, also known as Growth Hormone.
- Its primary function is to promote growth and development in the body.
- It does not play a role in the reabsorption of water in the kidneys.
- **Conclusion**: STH is not the correct option.

3. **Analyzing Option (b) ACTH**:
- ACTH stands for Adrenocorticotropic Hormone.
- This hormone is produced by the pituitary gland and stimulates the adrenal glands to release cortisol, especially during stress.
- It is not directly involved in the regulation of water reabsorption in the kidneys.
- **Conclusion**: ACTH is not the correct option.

4. **Analyzing Option (c) LH**:
- LH stands for Luteinizing Hormone.
- This hormone is primarily involved in regulating the reproductive system, particularly in the gonads (ovaries and testes).
- It does not have a role in kidney function or water reabsorption.
- **Conclusion**: LH is not the correct option.

5. **Analyzing Option (d) ADH**:
- ADH stands for Antidiuretic Hormone.
- As the name suggests, ADH is crucial for the reabsorption of water in the kidneys.
- It increases the permeability of the kidney tubules, allowing more water to be reabsorbed back into the bloodstream.
- This hormone helps to concentrate urine and maintain body fluid balance.
- **Conclusion**: ADH is the correct option.

6. **Final Answer**: The hormone that controls the reabsorption of water in the kidneys is (d) ADH.