2.2 Hormonal Control of Reproduction

How is onset of puberty triggered

The hypothalamus release releaser hormone targeted to the pituitary gland, stimulating the release of FSH (follicle stimulating hormone) and ICSH (interstitial cell-stimulating hormone) in men or LH (luteinising hormone) in women

State function of FSH in men

stimulate sperm production in the seminiferous tubules

State function of ICSH

stimulate production of testosterone in interstitial cells

State 3 functions of testosterone

- stimulate sperm production
- activate seminal vesicle and prostate gland for semen production
- negative feedback control - inhibit production of FSH and ICSH if testosterone level is high

State number of days in a menstrual cycle

28

How is day 1 of the menstrual cycle determined

by menstruation, day 1 = first day of period

State the significance of day 14

ovulation

State the 2 phases in the menstrual cycle

follicular (first half), luteal (second half)

State function of FSH in women

stimulate development and maturation of follicle in ovary

State source of oestrogen

ovary from developing follicles

State 2 functions of oestrogen

- proliferation (cell division/ growth of tissue) of endometrium to prepare for implantation
- thin cervical mucus for easier penetration by sperm

State cause of ovulation

surge of LH

What happens to the follicle after ovulation

develop into corpus luteum

State source of progesterone

corpus luteum

State function of progesterone

vascularisation (development of blood tissues) of endometrium

State outcome if fertilisation has not occur

high progesterone levels inhibit production of FSH and LH, lack of LH leads to degeneration of corpus luteum, leads to a drop in progesterone, the endometrium cannot be supported, menstruation occurs

State outcome if fertilisation occurred

embryo secret HCG (human chorionic gonadotrophin) which mimics effect of LH, continue supporting corpus luteum leading to high progesterone level for the endometrium