Biology Module 3 - 3.sexual reproduction in humans 3.6 explain how hormones regulate gametogenesis

3.6 explain how hormones regulate gametogenesis

LH - Luteinizing hormone
FSH - follicle stimulating hormone
GnRH - Gonadotropin-releasing hormone


spermatogenesis

• pituitary gland secretes LH which travels in the blood to the interstitial cells of the testes

• production of testosterone in the testes is then stimulated

• testosterone then stimulates spermatogenesis in the seminiferous tubules

• FSH is also secreted by the pituitary gland which binds to recpeptors on the membranes of the seritoli cells which then stimulates sperm development and the secretion of fluid into seminiferous tubules

• If testosterone levels increase there's decrease in GnRH production by hypothalamus which reduces levels of LH and FSH production

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oogeneis

• GnRH from the hypothalamus is produced which stimulates production of FSH. FSH stimulates development of primary follicle

• follicle stimulates oetrogen. Oestrogen stimulates repair and thickening of endometrium and inhibits secretion of LH and FSH

• GnRH is produced which produces a 'surge' of LH and FSH to stimulate ovulation. LH stimulates development of corpus luteum

• corpus luteum secretes progesterone and reduces oestrogen production. low levels of oestrogen reduces FSH and LH production

• corpus luteum secretes oestrogen and progesterone. progesterone stimulates glandular activity in endometrium and oestrogen helps maintain its thickness. This high level of progesterone inhibit GnRH, LH and FSH production

• if egg is not fertilzed, corpus luteum degenerates. oestrogen and progesterone is decreased. FSH is no longer inhibited so FSH stimulates formation of new primary follicle