The cyclic events that take place in a rhythmic fashion during the reproductive period of a woman’s life is called menstrual cycle. The menstrual cycle starts at the age of 12 to 15 years, which marks the onset of puberty. The commencement of menstrual cycle is called menarche. The menstrual cycle ceases at the age of 45 to 50 years. The permanent cessation of menstrual cycle in old age is called menopause.
DURATION OF MENSTRUAL CYCLE
The duration of menstrual cycle is usually 28 days. But, under physiological conditions, it may vary between 20 and 40 days.
CHANGES DURING MENSTRUAL CYCLE
During each menstrual cycle, series of changes occur in ovary and accessory sex organs. All these changes are divided into 4 groups for the convenience of description.