2.3 Hormones and Menstrual Cycle

The menstrual cycle in women is a recurring monthly process in which the lining of the uterus (the womb) is prepared for pregnancy. If pregnancy does not happen, the lining is shed at menstruation.

Follicle stimulating hormone, FSH

The hormone FSH is secreted by the pituitary gland.

• it causes an egg to mature in an ovary
• it stimulates the ovaries to release the hormone oestrogen.

Oestrogen

The hormone oestrogen is secreted by the ovaries.

• it stops FSH being produced - so that only one egg matures in a cycle
• it stimulates the pituitary gland to release luteinizing hormone (LH), which triggers ovulation (the release of the mature egg from the ovary)., it cause the Uterus linning to thicken.

Luteinising hormone, LH

Made in pituitary gland. It stimulates the mature egg to be released from the ovaries. (ovulation)