Which hormone is involved in the regulation of the menstrual cycle?

Luteinizing hormone plays a critical role in the regulation of the menstrual cycle. It is produced by the anterior pituitary gland and is essential for triggering ovulation, which occurs around the midpoint of the menstrual cycle. The surge in luteinizing hormone is what stimulates the mature ovarian follicle to release an egg, marking the transition from the follicular phase to the luteal phase of the cycle.

Additionally, luteinizing hormone works in conjunction with follicle-stimulating hormone (FSH) to regulate the development of ovarian follicles and the subsequent production of estrogen and progesterone, hormones that are crucial for preparing the uterine lining for potential implantation of a fertilized egg. The balanced interplay of these hormones is fundamental for a regular and healthy menstrual cycle.

The other hormones listed do not have a direct role in regulating the menstrual cycle. Prolactin is primarily involved in breast milk production and does not directly influence the timing of ovulation. Adrenaline is a stress hormone that prepares the body for a "fight or flight" response and does not play a role in menstrual regulation. Cortisol, also a stress hormone, can affect menstrual cycles but is not a primary regulator of the cycle itself. Thus, luteinizing hormone is