Definition of the word menstrual cycle

The term "menstrual cycle" refers to the physiological process that occurs in the uterus of female mammals, including humans. It is a complex and regulated process that prepares the body for possible pregnancy and sheds the uterine lining if fertilization does not occur. The menstrual cycle is divided into four phases: menstruation, follicular phase, ovulation, and luteal phase. Menstruation usually lasts around 3-7 days and involves the shedding of the uterine lining, also known as the endometrium, due to the withdrawal of progesterone and estrogen. The follicular phase begins after menstruation and lasts around 14 days. During this phase, a follicle in one of the ovaries grows and matures, releasing estrogen, which thickens the endometrium in preparation for potential fertilization. Ovulation, the release of a mature egg from the follicle, occurs around 14 days before the start of the next menstruation. As the follicle ruptures, it creates a small bleed, which leads to slight discomfort or pain, known as mild menstrual cramps. The final phase is the luteal phase, which lasts around 12-14 days. During this time, the empty follicle transforms into a structure called the corpus luteum, which releases progesterone in preparation for the implantation of a fertilized egg. If the egg does not implant, the corpus luteum breaks down, leading to the shedding of the endometrium and the start of the next menstrual cycle. In summary, the term "menstrual cycle" refers to the sequence of events that occurs in the uterus of females with the goal of preparing the body for pregnancy and facilitating its removal if fertilization does not occur.