Which hormones are primarily involved in regulating the menstrual cycle?

The hormones primarily involved in regulating the menstrual cycle are estrogen, progesterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). These hormones play distinct and crucial roles throughout the different phases of the menstrual cycle.

Estrogen is primarily responsible for the growth and maintenance of the uterine lining (endometrium) during the first half of the cycle, preparing it for a potential pregnancy. As the cycle progresses and ovulation approaches, estrogen levels rise sharply, triggering a surge in LH. This LH surge is essential for the process of ovulation itself, wherein a mature egg is released from the ovarian follicle.

Progesterone, produced by the corpus luteum after ovulation, helps to further thicken the uterine lining in preparation for a possible implantation of a fertilized egg. If pregnancy does not occur, progesterone levels drop, leading to the shedding of the uterine lining during menstruation.

Overall, the interplay between these hormones is fundamental to the regulation of the menstrual cycle, involving complex feedback mechanisms that ensure the proper timing of ovulation and menstruation.