A decrease in the level of estrogen and progesterone causes

Options

A. (1) growth and dilation of myometrium
B. (2) growth of endometrium
C. (3) constriction of uterine blood vessels leading to sloughing of endometrium or uterine epithelium
D. (4) release of ovum from the ovary

Answer

**Step-by-Step Solution:**

1. **Understanding Hormones**: Begin by defining the hormones in question. Estrogen and progesterone are key hormones in the female reproductive system. Estrogen is responsible for the development and maintenance of female characteristics, while progesterone plays a crucial role in regulating the menstrual cycle and maintaining pregnancy.

2. **Effects of Decreased Hormone Levels**: When the levels of estrogen and progesterone decrease, it impacts the reproductive system significantly. These hormones help maintain the uterine lining and regulate blood flow to the uterus.

3. **Consequences of Decreased Estrogen and Progesterone**: The decrease in these hormones leads to the constriction of uterine blood vessels. This constriction results in reduced blood flow to the endometrium (the inner lining of the uterus), causing it to become less nourished.

4. **Slugging of the Endometrium**: As a result of the constriction of blood vessels, the endometrium undergoes a process known as "slugging," where it becomes less viable and may eventually shed. This is part of the menstrual cycle where the uterine lining is expelled if pregnancy does not occur.

5. **Evaluating the Options**: Given the options provided:
- Option 1 (growth and dilation of the myometrium) is incorrect.
- Option 2 (growth of endometrium) is also incorrect.
- Option 3 (constriction of uterine blood vessels leading to the slugging of the endometrium) is correct.
- Option 4 (release of ovum from the ovary) is incorrect.

6. **Conclusion**: The correct answer is option 3, which states that a decrease in the level of estrogen and progesterone causes the constriction of uterine blood vessels leading to the slugging of the endometrium or uterine epithelium.

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