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Flashcards in Key Reproductive hormones Deck (18)
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1

what are the key reproductive hormones

GnRH, LH, FSH, Oestrogen, Progesterone, Testosterone

2

what is GnRH

Gonadotrophin Releasing Hormone

3

what are LH and FSH

LH = luteinising hormone
FSH = follicular stimulating hormone

4

what is the HPG axis found in both females and males

Hypothalamic Pituitary Gonadal(HPG) Axis

5

what are the 2 gonadotropic hormones released from the anterior pituitary

LH and FSH

6

describe the HPG axis in femlaes

Hypothalamus secretes GnRH, stimulates anterior pituitary to release LH and FSH, act on ovaries to release oestrogen and progesterone

7

describe the HPG axis in males

Hypothalamus secretes GnRH, stimulates anterior pituitary to release LH and FSH,, act on testes to release testosterone`

8

what is the function of FSH in males

causes the testes to produce sperm(spermatogenesis)

9

what is the function of FSH in females

causes the growth of ovarian follicles(oogenesis) and it causes the ovary to secrete oestrogen

10

what is thee function of LH in males

causes the testes to secrete testosterone

11

what is the function of LH in females

causes ovulation and causes progesterone production by the Corpus luteum

12

what type of feedback loop is seen in both male and female HPG axis

negative feedback loop

13

what type of hormone is GnRH and where is it synthesised and released

it is a neuropeptide hormone, synthesised and released from GnRH neurons in the hypothalamus

14

describe the release of GnRH in males

secreted in pulses at a constant frequency

15

describe the release of GnRH in females

frequency of pulses varies during menstrual cycle, pulses every 1-2hrs in early follicular phase, decreases in late follicular phase, and decreases to every 4hrs in luteal phase

16

describe how GnRH frequency affects LH and FSH release

high frequency GnRH pulses stimulate LH
low frequency GnRH stimulate FSH

17

what affect to oestrogen and progesterone have on GnRH

high oestrogen = increase GnRH pulsatiltiy, driving LH release
high progesterone = reduces GnRH frequency

18

describe how GnRH is regulated by oestrogen and progesterone

GnRH producing hormones don't have receptors for oestrogen or progesterone, they instead bind to Kisspeptin neurones, so indirect regulation