Hormones And The Menstrual Cycle

Question 1

What are the 4 hormones involved in the menstrual cycle

Answer 1

FSH - follicle stimulating hormone
LH - luteinising hormone
Oestrogen
Progesterone

Question 2

What does FSH do

Answer 2

Causes egg to mature

Stimulates ovary to produce oestrogen

Question 3

What does LH do

Answer 3

Triggers ovulation

Question 4

What does oestrogen do

Answer 4

Causes lining of uterus to develop
Inhibits release of FSH
Stimulates release of LH

Question 5

What does progesterone do

Answer 5

Maintains the lining of the uterus

Inhibits release of both FSH and LH

Question 6

What is the hormonal interaction in the menstrual cycle

Answer 6

1FSH released in pituitary causing egg to mature in ovary and stimulates ovary to produce oestrogen
2 oestrogen causes uterus lining to grow and stimulates release of LH and inhibits release of FSH
3 LH produced by pituitary and stimulates release of egg at day 14 of ovulation
4 progesterone produced in ovaries by remains of follicle after ovulation. Maintains uterus lining in second half of cycle. When it falls lining breaks down. It inhibits LH and FSH release

Question 7

What do the ovaries contain

Answer 7

All the eggs a baby girl will ever have
Released every 28 days after puberty
Except if pregnant
Continues 35-40 years
Then menopause and no longer have children
Approaching menopause less fertile but risk of genetic problems in baby

Question 8

What happens on day 0-5

Answer 8

A surge of hormones from the pituitary gland in the brain starts the egg maturation in the ovaries

Question 9

What happens days 6-12

Answer 9

FSH makes egg mature
Stimulates ovaries to produce oestrogen
Oestrogen inhibits FSH and stimulates LH

Question 10

What happens day 14

Answer 10

LH stimulates release of mature egg from ovary

After ovulation LH levels are high

Question 11

What happens day 15 to 24

Answer 11

Progesterone inhibits both FSH and LH after ovulation and maintains lining of uterus and stops release of FSH and LH

Question 12

If pregnant woman has a placenta that produces progesterone- why is this important for the embryo

Answer 12

1 Progesterone inhibits both LH and FSH
2 This prevents FSH being released and another egg being released from the ovary so another pregnancy doesn’t happen
3 Maintains lining of uterus so it is ready to receive
an embryo if an egg is fertilised