Key Reproductive hormones

Question 1

what are the key reproductive hormones

Answer 1

GnRH, LH, FSH, Oestrogen, Progesterone, Testosterone

Question 2

what is GnRH

Answer 2

Gonadotrophin Releasing Hormone

Question 3

what are LH and FSH

Answer 3

LH = luteinising hormone
FSH = follicular stimulating hormone

Question 4

what is the HPG axis found in both females and males

Answer 4

Hypothalamic Pituitary Gonadal(HPG) Axis

Question 5

what are the 2 gonadotropic hormones released from the anterior pituitary

Answer 5

LH and FSH

Question 6

describe the HPG axis in femlaes

Answer 6

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

Question 7

describe the HPG axis in males

Answer 7

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

Question 8

what is the function of FSH in males

Answer 8

causes the testes to produce sperm(spermatogenesis)

Question 9

what is the function of FSH in females

Answer 9

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

Question 10

what is thee function of LH in males

Answer 10

causes the testes to secrete testosterone

Question 11

what is the function of LH in females

Answer 11

causes ovulation and causes progesterone production by the Corpus luteum

Question 12

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

Answer 12

negative feedback loop

Question 13

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

Answer 13

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

Question 14

describe the release of GnRH in males

Answer 14

secreted in pulses at a constant frequency

Question 15

describe the release of GnRH in females

Answer 15

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

Question 16

describe how GnRH frequency affects LH and FSH release

Answer 16

high frequency GnRH pulses stimulate LH

low frequency GnRH stimulate FSH

Question 17

what affect to oestrogen and progesterone have on GnRH

Answer 17

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

Question 18

describe how GnRH is regulated by oestrogen and progesterone

Answer 18

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