AQA GCSE science on pages 28 & 29
The Menstrual Cycle
Females have Ovaries that develop and produce hormones whereas Males have Testes that develop and produce hormones although Females have a menstrual period each month.
- The pituitary gland in the brain produces a hormone called follicle stimulating hormone. (FSH)
- FSH causes eggs in the ovaries to mature, one each month.
- It also stimulates the ovaries to make Oestrogen.
- Oestrogen stimulates the pituitary gland to make luteinising hormone (LH), which triggers the release of an egg (ovulation) from the ovary.
- Oestrogen also prevents more FSH being secreted and it repairs the uterus lining after menstruation.
- Progesterone maintains the uterus lining and works with Oestrogen to prevent secretion of FSH.
If the egg is not fertilised at the end of the cycle the uterus lining passes out of the body. This is the period. If the egg is fertilised then the uterus lining stays so that the baby can develop.
How the Female sex hormones control fertility
The female sex hormone can be used to make a women less fertile, if she does not want to become pregnant.
During pregnancy both Oestrogen and Progesterone levels are high and they inhibit FSH production from the pituitary gland. This prevents the development and release of any more eggs.
Some women may not conceive easily and want to improve their fertility. FSH may be used to help them.
Although, if women do not want to conceive, the contraceptive pill would prevent ovulation as it contains Oestrogen and Progesterone.
Some women may not conceive easily and want to improve their fertility. FSH may be used to help them.
Although, if women do not want to conceive, the contraceptive pill would prevent ovulation as it contains Oestrogen and Progesterone.
Learning Objectives
Sex hormones, Oestrogen, Progesterone, Menstrual cycle, FSH, LH, Ovulation, Contraceptive. |
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