What is the primary hormone responsible for the regulation of the menstrual cycle?

• A. Progesterone
• B. Estrogen
• C. Testosterone
• D. Follicle Stimulating Hormone (FSH)

Answer: (B)

Estrogen plays a crucial role in the regulation of the menstrual cycle. It is primarily produced by the ovaries and is essential for the development and maintenance of the female reproductive system and secondary sexual characteristics. During the menstrual cycle, estrogen levels fluctuate, leading to the growth of the endometrial lining in preparation for a potential pregnancy.

As the follicle develops in the ovarian cycle, it produces increasing amounts of estrogen, which ultimately triggers a surge in luteinizing hormone (LH), leading to ovulation. Following ovulation, estrogen continues to influence the cycle by collaborating with progesterone to maintain the endometrium. If pregnancy does not occur, the decrease in estrogen levels signals the onset of menstruation.

While other hormones listed also have important functions in the menstrual cycle, such as progesterone's role in maintaining the uterine lining post-ovulation and FSH's involvement in follicle development, estrogen is the primary hormone that coordinates these events and drives the cyclical changes of the menstrual cycle.