Menstrual Cycle

Key Stage 3

Meaning

The menstrual cycle is the changes that happen to the female reproductive system every 28 days (actually the average is 31 days, but textbooks have put it as 28 for simplicity).

About the Menstrual Cycle

The menstrual cycle in humans repeats every month.


In the first 6 days of the menstrual cycle the uterine wall leaves through the vagina. This is often called a 'period'.	On day 7 an ovum begins to mature and the uterine wall starts to build back up again.	The uterine wall continues to build up.	The uterine wall continues to build up.

The uterine wall continues to build up.	The ovum is released from the ovary.	The ovum travels down the oviduct.	If the ovum is not fertilised the uterine wall breaks down.


A graph showing the relative thickness of the uterine wall through the 28 days of the menstrual cycle.

Key Stage 4

Meaning

The menstrual cycle is a regular change in the organs of the female reproductive system that include ovulation and menstruation (periods).

About the Menstrual Cycle

The menstrual cycle is controlled by the hormones; oestrogen, progesterone, luteinising hormone and follicle stimulating hormone.


A graph showing changes during the menstrual cycle in: The stages of follicle growth and ovulation. The body temperature. The hormone levels. The relative thickness of the uterine wall.