The hormone which regulates the growth of mammary gland and formation of milk in them is secreted by

Options

A. The gland attached to the hypothalamus by a stalk
B. The gland situated at the base of diencephalon
C. The gland situated near the trachea
D. The gland situated near the aorta

Answer

To solve the question regarding the hormone that regulates the growth of mammary glands and the formation of milk, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Hormone**: The question asks about a hormone that regulates the growth of mammary glands and the formation of milk. The hormone responsible for this function is **prolactin**.

2. **Locate the Source of Prolactin**: Prolactin is secreted by a specific gland in the body. We need to determine which gland produces this hormone.

3. **Consider the Options Provided**:
- **Option a**: The gland attached to the hypothalamus by a stalk (this refers to the pituitary gland).
- **Option b**: The gland situated at the base of the diencephalon (this is also the pituitary gland).
- **Option c**: The gland situated near the trachea (this refers to the thyroid gland).
- **Option d**: The gland situated near the aorta (this refers to the adrenal glands).

4. **Determine the Correct Answer**: The pituitary gland is known to be a pea-sized gland located at the base of the brain, just below the hypothalamus, and it is indeed attached to the hypothalamus by a stalk. Since prolactin is secreted by the pituitary gland, the correct answer is **Option a**.

5. **Final Answer**: The hormone which regulates the growth of mammary glands and formation of milk in them is secreted by **the gland attached to the hypothalamus by a stalk (the pituitary gland)**.