Key Area 2.2 - Hormonal Control of Reproduction

Question 1

What are hormones?

Answer 1

Chemical messengers produced the endocrine glands.

Question 2

Where are hormones released?

Answer 2

Directly into the bloodstream and travel to their target tissue or organ where they have their effect.

Question 3

What do hormones control?

Answer 3

The onset of puberty, sperm production and the menstrual cycle.

Question 4

What does the hypothalamus secret at puberty?

Answer 4

A released hormone that targets the pituitary gland.

Question 5

What hormones are released when the pituitary gland is stimulated?

Answer 5

Follicle stimulating hormone (FSH), luteinising hormone (LH) in women and interstitial cell stimulating hormone (ICSH) in men.

Question 6

What does FSH promote?

Answer 6

Sperm production in the seminiferous tubules of the testes.

Question 7

What does ICHS stimulate?

Answer 7

The interstitial cells in the testes to produce the male sex hormone called testosterone.

Question 8

What does testosterone stimulate?

Answer 8

Sperm production in the seminiferous tubules and also activates the prostate gland and the seminal vesicles to produce their fluid secretions.

Question 9

What is overproduction of testosterone prevented by?

Answer 9

Negative feedback.

Question 10

Explain negative feedback.

Answer 10

High testosterone levels inhibit the secretion of FSH and ICSH from the pituitary gland, resulting in a decrease in the production of the testosterone by the interstitial cells.

Question 11

What hormones are associated with the menstrual cycle?

Answer 11

FHS
LH
Oestrogen
Progesterone

Question 12

Describe what happens in the follicular phase of the menstrual cycle.

Answer 12

FSH stimulates the development and maturation of follicle surrounding the ovum and the production of the sex hormone oestrogen by the follicle.

Question 13

What does oestrogen stimulate?

Answer 13

The repair and vascularisation of the endometrium, thickening it and preparing it for implantation.

Question 14

Describe what happens in the literal phase.

Answer 14

A surge of LH triggers ovulation and then stimulates the development of the corpus luteum from the follicle.

Question 15

What does LH stimulate?

Answer 15

The corpus luteum to secrete the sex hormone progesterone.

Question 16

What does progesterone promote?

Answer 16

The dither development and vascularisation of the endometrium preparing it for implantation of a blastocyst, if fertilisation occurs.

Question 17

What does high levels of oestrogen and progesterone inhibit?

Answer 17

The secretion of FSH and LH by the pituitary gland, this prevents further follicles from developing.

Question 18

Describe negative feedback in females.

Answer 18

The inhibition of FSH and LH by high levels of oestrogen and progesterone.

Question 19

What happens if fertilisation doesn’t occur?

Answer 19

There is a drop in LH levels which causes the corpus luteum to break down, in turn causing a decrease in progesterone and oestrogen levels.

Question 20

What triggers menstruation?

Answer 20

The decrease in oestrogen and progesterone levels which causes the endometrium to break down.