B5 Hormones In Reproduction

Question 1

What do hormones regulate in reproduction?

Female

Answer 1

The menstrual cycle

Question 2

List 4 stages of menstrual cycle

Answer 2

Stage 1 - day 1 menstruation starts
(The lining of the uterus breaks down and is released)

Stage 2 - the uterus lining is repaired
(From day 4 to day 14, until it becomes a thick sponge layer full of blood vessels ready for a fertilised egg to implant there.)

Stage 3 - an egg develops and is released
(Egg is released from the ovary (ovulation) at about day 14)

Stage 4 - the lining is then maintained until day 28

Question 3

What is the release of the egg from the ovary called?

Answer 3

Ovulation

Question 4

What hormones control the menstrual cycle?

Answer 4

FSH (Follicle-stimulating hormone)

Oestrogen

LH (luteinising hormone)

Progesterone

Question 5

Where is FSH released from?

Answer 5

Pituitary gland

Question 6

What affect does FSH have?

Answer 6

It causes a follicle to mature in one of the ovaries?

Question 7

What is a follicle?

Answer 7

An egg and it’s surrounding cells

Question 8

What hormone is stimulated by FSH?

Answer 8

Oestrogen

Question 9

Where is oestrogen released from?

Answer 9

The ovaries

Question 10

What affect does oestrogen have?

Answer 10

It causes the lining of the uterus to thicken and grow.

Question 11

Where is LH released by?

Answer 11

The pituitary gland

Question 12

What does the release of LH do?

Answer 12

A LH surge stimulates ovulation at day 14, the follicle ruptures and the egg is released.

It stimulates the remains of the follicle to develop into a structure called a corpus lute up, which secretes progesterone.

Question 13

Where is progesterone released by?

Answer 13

The ovaries

Question 14

What does progesterone do?

Answer 14

Maintains the lining of the uterus for the implantation of a fertilised egg.

Question 15

What inhibits the release of FSH and LH?

Answer 15

Oestrogen and progesterone.

Question 16

What happens when the level of progesterone falls?

Answer 16

The uterus lining breaks down.

Question 17

When there is a low progesterone level what other hormone increases?

Answer 17

FSH

Question 18

What happens if a fertilised egg implants in the uterus?

Answer 18

The woman becomes pregnant and the level of progesterone will stay high to maintain the lining of the uterus during pregnancy.

Question 19

Explain the role of LH in the menstrual cycle. (2 marks)

Answer 19

LH stimulates the release of an egg/ovulation (1 mark)

It also stimulates the remains of the follicle to secrete progesterone (1 mark)