Hormonal Control Of Reproduction

Question 1

What type of glands are the hypothalamus and pituitary gland?

Answer 1

Endocrine glands found in the brain

Question 2

What triggers the onset of puberty?

Answer 2

The hypothalamus releases a hormone called the ‘releaser hormone’ which targets the pituitary gland. It stimulates the pituitary gland to release follicle stimulating hormone (FSH)(female and male), luteinising hormone(LH)(female) and interstitial cells stimulating hormone(ICSH)(male), these trigger the onset of puberty

Question 3

What does FSH promote?

Answer 3

The production of sperm in the seminiferous tubules Testosterone

Question 4

What does ICSH promote?

Answer 4

The production of testosterone in the interstitial cells

Question 5

What does testosterone stimulate?

Answer 5

Testosterone further stimulates sperm production and activated the prostate gland and seminal vesicles

Question 6

What is negative feedback control?

Answer 6

A self regulating mechanism in the body to control many processes

Question 7

What happens during the negative feedback of testosterone?

Answer 7

There’s a build up of testosterone in the blood, when it reaches a certain concentration it inhibits the secretion of FSH and ICSH in the pituitary gland
The reduction in FSH and ICSH causes a decrease in testosterone
The reduction then stops the inhibition oh the pituitary gland
Resulting in and increase in FSH and ICSH stimulating an increased production of testosterone
(CYCLE)

Question 8

How long does the menstrual cycle approximately take?

Answer 8

28 days with the first day of menstruation regarded as day one of the cycle

Question 9

What two phases can the cycle be divide into?(what days are they?(approximately)

Answer 9

The follicular phase(1-14)
The luteal phase(14-28)

Question 10

What happens during the follicular phase?

Answer 10

FSH released by the pituitary stimulate the development of the follicle
FSH then stimulates the production
of oestrogen by the follicle in the follicular phase
Oestrogen stimulated the proliferation of the endometrium preparing it for implantation
Oestrogen also affects the consistency of cervical mucus making it more easily penetrated by sperm
Peak levels of oestrogen stimulate a surge of levels of LH which triggers ovulation
(Ovulation on next card)

Question 11

What is ovulation and when does it happen?

Answer 11

Ovulation is the releases of an egg(ovum) from a follicle in the ovary
Usually day 14(midpoint of menstrual cycle)

Question 12

What happens during the luteal phase?

Answer 12

The follicle develops into a corpus luteum
The corpus luteum then secrets progesterone
Progesterone promotes further development and vascularisation of the endometrium preparing it for implantation if fertilisation occurs

Question 13

What happens during the negative feedback effect when fertilisation doesn’t occur in the luteal phase?

Answer 13

Combined high levels of ovarian hormones trigger an inhibitory effect on the pituitary gland
The negative feedback effect of the ovarian hormones on the pituitary gland and the secretion of FSH and LH prevent further follicles from developing
The lack of LH leads to degeneration of the corpus luteum with a subsequent drop in progesterone levels leading to menstruation

Question 14

What happens if implantation doesn’t occur?

Answer 14

The embryo will be removed during menstruation

Question 15

What happens if fertilisation occurs?

Answer 15

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