What Is The Menstrual Cycle? | Physiology | Biology | FuseSchool

Women, usually between the ages of 12 and 50 years old, undergo a monthly cycle in which their uterus prepares for pregnancy; it prepares for a fertilised egg to settle and grow into a baby.

If pregnancy does not occur, the lining breaks down and is expelled from the uterus. This is known as menstruation.