Unit 2 - Gamete production & fertilisation Hormonal control of reproduction Key Area 1 & 2

Question 1

What does the testes produce?

Answer 1

Testes produce sperm in the seminiferous tubules and testosterone in the interstitial cells

Question 2

What does the prostate gland and seminal vesicles do?

Answer 2

The prostate gland and seminal vesicles secrete fluids that maintain the mobility and viability of the sperm.

Question 3

What do ovaries contain and what is a follicle?

Answer 3

The ovaries contain immature ova in various stages of development. Each ovum is surrounded by a follicle that protects the developing ovum and secretes hormones.

Question 4

Describe fertilisation

Answer 4

Mature ova are released into the oviduct where they may be fertilised by sperm to form a zygote. (The nucleus of the sperm and egg fuses together to form a zygote.)

Question 5

a) What does the pituitary gland do ?
b) What causes it to act that way?
c) Whats the consequence of that act?

Answer 5

The pituitary gland is stimulated to release follicle stimulating hormone (FSH), luteinising hormone (LH) or interstitial cell stimulating hormone (ICSH) by a releaser hormone produced in the hypothalamus. This triggers the onset of puberty.

Question 6

What does FSH stand for?

Answer 6

Follicle stimulating hormone

Question 7

What does LH stand for?

Answer 7

Luteinising hormone

Question 8

What does ICSH stand for

Answer 8

Interstitial cell stimulating hormone

Question 9

What is the function of Follicle stimulating hormone (FSH)?

Answer 9

FSH promotes sperm production

Question 10

What does Interstitial cell stimulating hormone (ICSH) stimulate?

Answer 10

ICSH stimulates the production of the hormone testosterone.

Question 11

What does testosterone stimulate?

Answer 11

Testosterone also stimulates sperm
production and activates the prostate gland
and seminal vesicles

Question 12

What do FSH and ICSH control?

Answer 12

Negative feedback control of testosterone by FSH and ICSH

Question 13

Describe the menstrual cycle?

Answer 13

The menstrual cycle takes approximately 28
days with the first day of menstruation
regarded as day one of the cycle.

Question 14

What does Oestrogen stimulate?

Answer 14

Oestrogen stimulates proliferation of the endometrium preparing it for implantation, and affects the consistency of cervical mucus making it more easily penetrated by sperm.

Question 15

What do peak levels of oestrogen stimulate?

Answer 15

Peak levels of oestrogen stimulate a surge in the secretion of LH. This surge in LH triggers ovulation.

Question 16

What is ovulation?

Answer 16

Ovulation is the release of an egg (ovum) from a follicle in the ovary. It usually occurs around the mid-point of the menstrual cycle.

Question 17

What happens in the luteal phase of ovulation?

Answer 17

In the luteal phase the follicle develops into a corpus luteum which secretes progesterone.

Question 18

What does Prgesterone promote in the luteal stage of ovulation?

Answer 18

Progesterone promotes further development and vascularisation of the endometrium preparing it for implantation if fertilisation occurs.

Question 19

What does the negative feedback of ovarian hormones do?

Answer 19

The negative feedback effect of the ovarian hormones on the pituitary gland and the secretion of FSH and LH prevent further follicles from developing.

Question 20

What does the negative feedback of ovarian hormones do?

Answer 20

The negative feedback effect of the ovarian
hormones on the pituitary gland and the
secretion of FSH and LH prevent further
follicles from developing.

Question 21

What does a lack of LH lead to?

Answer 21

The lack of LH leads to degeneration of the corpus luteum with a subsequent drop in progesterone levels leading to menstruation.

Question 22

What happens to the corpus luteum if fertilisation does occur?

Answer 22

If fertilisation does occur the corpus luteum
does not degenerate and progesterone levels
remain high.