Which of the following is secreted by follicular cells during proliferative phase?

Options

A. Estrogen
B. Inhibin
C. FSH
D. Both (1) & (2)

Answer

To solve the question "Which of the following is secreted by follicular cells during the proliferative phase?" we need to analyze the options provided and understand the role of follicular cells during the proliferative phase of the menstrual cycle.

### Step-by-Step Solution:

1. **Understand the Proliferative Phase**:
- The proliferative phase occurs after menstruation and before ovulation, typically from days 5 to 13 of the menstrual cycle. During this phase, the endometrium (lining of the uterus) thickens in preparation for potential implantation of a fertilized egg.

2. **Identify the Role of Follicular Cells**:
- Follicular cells are found in the ovarian follicles and are responsible for producing hormones that regulate the menstrual cycle.

3. **Hormones Secreted by Follicular Cells**:
- **Estrogen**: During the proliferative phase, the developing follicles (specifically the Graafian follicle) secrete estrogen, which plays a crucial role in the thickening of the endometrium.
- **Inhibin**: Follicular cells also secrete inhibin, which helps regulate the secretion of FSH (Follicle Stimulating Hormone) and prevents the maturation of multiple follicles.

4. **Evaluate the Options**:
- a. Estrogen: Correct, as it is secreted by follicular cells during this phase.
- b. Inhibin: Correct, as it is also secreted by follicular cells during this phase.
- c. FSH: Incorrect, as FSH is secreted by the pituitary gland, not by follicular cells.
- d. Both 1 and 2: Correct, since both estrogen and inhibin are secreted by follicular cells.

5. **Conclusion**:
- The correct answer is option D, which states that both estrogen and inhibin are secreted by follicular cells during the proliferative phase.

### Final Answer:
**Option D: Both 1 and 2 (Estrogen and Inhibin)**