Menstrual Cycle
Contents
Key Stage 3
Meaning
The menstrual cycle is the changes that happen to the female reproductive system every 28 days.
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:
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- Oestrogen and Progesterone - Secreted by the ovaries in females and causes the lining of the uterus to become thicker during the menstrual cycle.
- Luteinising Hormone - Secreted by the pituitary gland in females and causes an ovum to be released from a follicle in the ovaries.
- Follicle Stimulating Hormone - Secreted by the pituitary gland in females and causes follicles to grow in the ovaries and stimulates the production of oestrogen.