The four hormones of the menstrual cycle, how they control each other, contraception and IVF.
What you will learn
- Say what FSH, LH, oestrogen and progesterone do and where they are made
- Read a hormone graph of the menstrual cycle
- Compare methods of contraception using data
- Describe IVF and its risks (Higher)
The menstrual cycle
At puberty, oestrogen (girls) and testosterone (boys) bring on the changes of adolescence.
In women a cycle of about 28 days is controlled by four hormones:
| Hormone | Made in | Job |
|---|---|---|
| FSH | pituitary gland | an egg matures in an ovary |
| LH | pituitary gland | triggers ovulation (release of the egg) |
| oestrogen | ovaries | uterus lining builds up again |
| progesterone | ovaries | keeps the lining thick |
On a graph of the cycle, ovulation is at the sharp peak of LH, around the middle. When progesterone falls at the end, the lining breaks down and a period starts. If the woman becomes pregnant, the progesterone level stays high, so the lining stays thick and there is no period.
Higher: the hormones control each other. FSH stimulates the ovaries to make oestrogen; oestrogen inhibits FSH and stimulates LH; progesterone inhibits both FSH and LH.
FSH makes the egg mature; LH makes it leave the ovary. Both come from the pituitary, not the ovary.
The rest of this lesson and its 10 practice questions are locked.
In this lesson
- The menstrual cycle
- Contraception
- Higher: treating infertility
- Try it: Read a hormone graph
10 practice questions, marked as you go; about 25 minutes in all.
Key terms
Intrauterine devices, Spermicides, Surgical, Effectiveness, IVF
In this unit: Homeostasis and response
How the nervous and hormonal systems keep the body's internal conditions steady: reflexes and reaction time, blood glucose and diabetes, reproductive hormones and contraception, the brain, eye, temperature and kidneys, and plant hormones.