During menstrual phase, uterine endomestrium, epthelial glands and connective tissues are broken. This is due to

Options

A. Over production of progesterone
B. Lack of progesterone
C. Over secretion of FSH
D. Lack of estrogen.

Answer

**Step-by-Step Solution:**

1. **Understanding the Menstrual Phase**: The menstrual phase is part of the menstrual cycle where the uterine lining (endometrium), epithelial glands, and connective tissues are shed if fertilization does not occur.

2. **Hormonal Regulation**: The menstrual cycle is regulated by hormones, primarily estrogen and progesterone. These hormones play crucial roles in preparing the endometrium for potential implantation of a fertilized egg.

3. **Role of Progesterone**: Progesterone is produced by the corpus luteum after ovulation. It helps maintain the endometrium and prevents its breakdown. If pregnancy does not occur, the corpus luteum degenerates, leading to a decrease in progesterone levels.

4. **Consequences of Low Progesterone**: When progesterone levels drop, the support for the endometrium is lost. This causes the endometrial lining to break down and be shed, leading to menstruation.

5. **Identifying the Cause**: The question asks for the reason behind the breakdown of the uterine endometrium, epithelial glands, and connective tissues during the menstrual phase. Since this breakdown occurs due to the lack of progesterone, the correct answer is option B.

6. **Conclusion**: The breakdown of the uterine lining during the menstrual phase is primarily due to the lack of progesterone, which is essential for maintaining the endometrial tissue.

**Final Answer**: The breakdown of the uterine endometrium, epithelial glands, and connective tissues during the menstrual phase is due to the lack of progesterone (Option B).

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