which part of mammary gland in humans secrete milk and which hormone is mainly involved in it

Answer

To answer the question regarding which part of the mammary gland in humans secretes milk and which hormone is mainly involved in this process, we can break it down into clear steps:

### Step-by-Step Solution:

1. **Understanding the Structure of the Mammary Gland**:
- The mammary gland consists of various tubules that lead to bulb-like structures known as alveoli.

2. **Identifying the Function of Alveoli**:
- The alveoli are the functional units of the mammary gland responsible for the production and secretion of milk. They are lined with milk-secreting cells that synthesize and release milk.

3. **Hormonal Regulation of Milk Secretion**:
- The secretion of milk is primarily regulated by hormones. Two key hormones involved in this process are:
- **Progesterone**: This hormone plays a role in the development of the mammary glands during pregnancy.
- **Prolactin**: This hormone is crucial for the production of milk after childbirth.

4. **Conclusion**:
- The part of the mammary gland that secretes milk is the **alveoli**.
- The hormone mainly involved in milk secretion is **prolactin**.

### Final Answer:
- The part of the mammary gland that secretes milk is the **alveoli**, and the hormone mainly involved in this process is **prolactin**.