KA2 - Hormonal Control Of Reproduction

Question 1

At puberty, what secretes a releaser hormone and what does it target?

Answer 1

The hypothalamus secretes a releaser hormone that targets the pituitary gland

Question 2

The releaser hormone stimulates the pituitary gland to release what other hormones to control the onset of puberty?

Answer 2

• follicle stimulating hormone
• luteinising hormone
• interstitial cell stimulating hormone

Question 3

What are the 3 hormones involved in the production of sperm?

Answer 3

• follicle stimulating hormone
• interstitial cells stimulating hormone
• testosterone

Question 4

What is the function of follicle stimulating hormone?

Answer 4

Promotes sperm production in seminiferous tubules

Question 5

What is the function of interstitial cell stimulating hormone?

Answer 5

Stimulates interstitial cells to produce testosterone

Question 6

What is the function of testosterone?

Answer 6

Stimulates sperm production and activates the prostate gland and seminal vesicles to release their secretions

Question 7

What is negative feedback control?

Answer 7

Negative feedback control is the system of maintaining a steady state in various body systems

Question 8

What is negative feedback control used for in the male reproductive system?

Answer 8

Regulate sperm production

Question 9

What are the 4 stages involved in negative feedback control of the male reproductive system?

Answer 9

1. FSH and ICSH released from the pituitary gland stimulate the seminiferous tubules and interstitial cells.
2. This causes the interstitial cells to produce testosterone.
3. High levels of testosterone have an inhibitory effect on the pituitary gland which inhibits the release of FSH and ICSH.
4. Testosterone levels then decrease and the cycle begins again.

Question 10

What are the 4 hormones involved in the control of the menstrual cycle?

Answer 10

• follicle stimulation hormone
• luteinising hormone
• oestrogen
• progesterone

Question 11

How would you describe male fertility

Answer 11

Males are continuously fertile

Question 12

How would you describe female fertility

Answer 12

Cyclical

Question 13

What are the 2 phases of the menstrual cycle?

Answer 13

• follicular phase

* luteal phase

Question 14

What is menstruation

Answer 14

Menstruation is the shedding of the endometrium, the blood lining of the uterus

Question 15

When does the follicular phase occur?

Answer 15

The first half of the menstrual cycle

Question 16

Explain the follicular phase

Answer 16

FSH stimulates the development of a follicle and the production of oestrogen by the follicle.

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

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

Question 17

When does the luteal phase occur?

Answer 17

After ovulation, during the second half of the menstrual cycle

Question 18

Explain the luteal phase

Answer 18

LH causes the follicle to develop into the corpus luteum which secretes progesterone.

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

Question 19

What is vascularisation?

Answer 19

The process by which there is an increase in blood vessels in the endometrium making it spongy

Question 20

Explain negative feedback control of the female reproductive system

Answer 20

High levels of oestrogen and progesterone have an inhibitory affect on the pituitary gland.

This decreases the levels of FSH and LH which prevents further follicles from developing.

If fertilisation does not occur, the ovum will degenerate which leads to the degeneration of the corpus luteum which stops secreting progesterone.

There is a subsequent drop in progesterone which leads to menstruation.

If fertilisation does occur, the corpus luteum will continue to secrete progesterone which prevents the release of FSH and new follicles developing.