Brainlag PlusThe four hormones of the menstrual cycle, how they control each other, contraception and IVF.
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.
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 in Plus.
Screen 1 of 4, free to read.
- 10 exam-style questions, marked as you go, each with a worked solution
- Anything you get wrong is saved to your flashcards