B11.6 Hormones and the menstrual cycle

Question 1

How long is the menstrual cycle?

Answer 1

28 days
14 days after the eggs start maturing one is released from the ovary in ovulation - lining of the uterus stays thick for several days after the egg has been released

Question 2

What happens if the egg is fertilised?

Answer 2

Lining of the uterus provides protection and food for the developing embryo.

Question 3

What happens if the egg is not fertilised?

Answer 3

14 days after ovulation the lining of the uterus and the egg are shed from the body in the monthly period

Question 4

What happens once a month?

Answer 4

A surge of hormones from the pituitary gland in the brain starts egg maturation in the ovaries. Also stimulate the ovaries to produce the female sex hormone Oestrogen

Question 5

What happens after the Pituitary gland released FSH?

Answer 5

FSH is secreted by the Pituitary gland. Makes eggs mature in the ovaries. Also stimulates ovaries to produce oestrogen

Oestrogen is made and secreted. Stimulates lining of the uterus to grow again after menstruation to prepare for pregnancy - High levels of oestrogen inhibit the production of more FSH and stimulate the release of LH

LH from the pituitary gland stimulates the release of the mature egg from the ovary. Once ovulation takes place LH levels fall again

Question 6

When is Progesterone released?

Answer 6

Released by the empty egg follicle in the ovary after ovulation. One of the hormones that helps maintain a pregnancy if the egg is fertilised.

Question 7

What does Progesterone contain?

Answer 7

Inhibit both FSH and LH and it maintains the lining of the uterus in the second half so it is ready to receive a developing embryo if the egg is fertilised

Question 8

What happens as oestrogen level rises?

Answer 8

Inhibit the production of FSH and increase production of LH by the pituitary gland. When LH levels rea ch a peak in the middle of the cycle they stimulate they release of a mature egg