Which hormone is primarily responsible for the regulation of the menstrual cycle?

• A. Estrogen
• B. Progesterone
• C. Luteinizing hormone
• D. Follicle-stimulating hormone

Answer: (A)

The hormone primarily responsible for the regulation of the menstrual cycle is estrogen. Estrogen plays a crucial role in the development and maintenance of the female reproductive system and secondary sexual characteristics. It is produced mainly by the ovaries and is involved in several stages of the menstrual cycle.

During the follicular phase, estrogen levels begin to rise as follicles develop in the ovaries. This hormone stimulates the growth of the endometrial lining, preparing it for a potential implantation of a fertilized egg. Estrogen also exerts negative feedback on the pituitary gland to regulate the secretion of other hormones, such as luteinizing hormone (LH) and follicle-stimulating hormone (FSH), particularly as ovulation approaches.

Near the midpoint of the cycle, a significant surge in estrogen levels can trigger the LH surge that leads to ovulation. After ovulation, the corpus luteum forms and produces progesterone, which is essential for maintaining pregnancy if fertilization occurs. While both estrogen and progesterone are important for the menstrual cycle, estrogen has a more prominent role in the initial phases and the overall regulation of the cycle.

In summary, estrogen is the key hormone responsible for the regulation of the menstrual cycle, influencing multiple processes, including the preparation of the uter