Effect of prolactin hormone is on

Options

A. Liver
B. Pancreas
C. Mammary glands
D. Bones.

Answer

### Step-by-Step Solution

1. **Understanding Prolactin**: Prolactin is a hormone also known as lactotropin. It is primarily involved in the production of milk in mammals, particularly in females.

2. **Source of Prolactin**: Prolactin is secreted by the pituitary gland, which is located at the base of the brain.

3. **Triggers for Secretion**: The secretion of prolactin occurs in response to various stimuli such as eating, mating, estrogen treatment, ovulation, and nursing. It is released in pulses during these events.

4. **Primary Function**: The main function of prolactin is to stimulate the mammary glands to produce milk. This is crucial for lactation in females after childbirth.

5. **Effects on Mammary Glands**: Prolactin causes the enlargement of mammary glands during pregnancy, preparing them for milk production. The production of milk typically begins when the levels of progesterone fall after childbirth.

6. **Other Roles**: In addition to its primary role in lactation, prolactin is also involved in metabolism, immune system regulation, and pancreatic development.

7. **Evaluating Options**:
- **Liver**: Prolactin does not primarily act on the liver.
- **Pancreas**: Prolactin does not primarily act on the pancreas.
- **Mammary Gland**: This is the correct answer as prolactin directly stimulates milk production in the mammary glands.
- **Bones**: Prolactin does not have a significant effect on bones.

8. **Conclusion**: The correct answer to the question regarding the effect of prolactin hormone is the mammary gland.

### Final Answer
The effect of prolactin hormone is primarily on the **mammary gland**.

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