Milk ejection from the mammary glands is induced by:

Options

A. Prolactin
B. Oxytocin
C. Vasopressin
D. Prolactin releasing hormone

Answer

**Step-by-Step Solution:**

1. **Understanding Milk Ejection**: Milk ejection from the mammary glands is a physiological process that occurs primarily after childbirth (parturition). This process is crucial for breastfeeding.

2. **Role of Hormones**: The process of milk ejection is primarily induced by hormones. The two main hormones involved are Prolactin and Oxytocin.

3. **Prolactin**:
- Prolactin is secreted by the anterior pituitary gland and is responsible for initiating milk production in the mammary glands.
- It is released in response to the hormone Human Placental Lactogen (HPL), which increases before childbirth.

4. **Oxytocin**:
- Oxytocin is another hormone that plays a vital role in the milk ejection reflex. It is released in response to suckling by the infant.
- Oxytocin causes the contraction of myoepithelial cells around the mammary glands, leading to the ejection of milk.

5. **Colostrum**: The first milk produced after childbirth is known as colostrum, which is rich in antibodies and provides passive immunity to the newborn.

6. **Conclusion**: In summary, milk ejection from the mammary glands is primarily induced by the hormone Prolactin, with Oxytocin facilitating the ejection process.

**Final Answer**: Milk ejection from the mammary glands is induced by the hormone Prolactin.

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