APEA Pharmacology Women's Health Practice Test

The primary hormone involved in the menstrual cycle is estrogen. Estrogen plays a crucial role in regulating various phases of the menstrual cycle, particularly in the follicular phase. It is responsible for the development and maturation of ovarian follicles, which are the structures that contain the eggs. As estrogen levels rise, they trigger a cascade of events that lead to the thickening of the uterine lining in preparation for a potential pregnancy.

While other hormones, such as progesterone and luteinizing hormone, also play significant roles in the menstrual cycle, estrogen is fundamental for the initial stages. Progesterone becomes more prominent after ovulation, helping to maintain the uterine lining, while luteinizing hormone is crucial for triggering ovulation itself. However, it is estrogen that primarily drives the changes during the early part of the cycle, making it the central hormone to consider when discussing the menstrual cycle overall.