Sex Steroids Biochemistry

Question 1

What are the pituitary gonadotrophic n hormones

Answer 1

FSH

LH

Question 2

whats the role of FSH in women

Answer 2

stimulates the development of the follicle

stimulates the release of oestrogen

Question 3

what is the role of FSH in men

Answer 3

regulates spermatogenesis

Question 4

What roll does LH play in women

Answer 4

stimulates ovulation and production of progesterone from the corpus luteum

Question 5

what does LH do in men

Answer 5

stimulates production of testosterone

Question 6

what has a -ve feedback effect on the pituitary/hypothalamus in men

Answer 6

testosterone

Question 7

what has a -ve feedback affect on the pituitary/hypothalamus in women

Answer 7

oestrogen

also has a +ve feedback affect at times

Question 8

what is the role of Gonadotrophin releasing hormone

Answer 8

secreted by the hypothalamus to target the pituitary causing the release of FSH and LH

Question 9

what is GnRH released in a pulsatile manner

Answer 9

because increased pulse frequency causes LH secretion and decreased pulse frequency causes FSH production

Question 10

what are GnRH pulses like in men

Answer 10

constant and don’t vary

Question 11

what hormone regulates the change in pulse rate from low to high (FSH to LH)

Answer 11

oestrogen

Question 12

what hormones regulates GnRH frequency from high to low (LH back to FSH)

Answer 12

progesterone

Question 13

what happens to GnRH in puberty

Answer 13

A steady acceleration of pulsatility

a peak at night in males causing high testosterone levels in the morning

Question 14

What regulates GnRH

Answer 14

Kisspeptin

Question 15

which phase of the menstrual cycle is variable

Answer 15

follicular

typically 14 days (+/- 7 days)

Question 16

which phase of the menstrual cycle isn’t variable

Answer 16

luteal (14 days)

Question 17

how does FSH cause oestrogen increase

Answer 17

is causes the follicle to develop and secrete oestrogen

Question 18

what stimulates ovulation

Answer 18

high oestrogen levels causing the LH surge

Question 19

what is a follicle

Answer 19

a oocyte surrounded by follicular cells (granulosa and theca cells)

Question 20

what happens as the follicle grows

Answer 20

increase in the number of follicular cells but still only 1 oocyte

Question 21

why do the follicular cells fill with cholesterol in folliculogenesis

Answer 21

so that they can produce and pump out loads of progesterone

follicular cells become luteal cells

Question 22

When multiple eggs are going through folliculogenisis how is one picked for ovulation

Answer 22

early stages of ovulogeneiss is independent on gonadotrophin

once it reaches a certain size it becomes dependent

when the FSH levels dip some follicles are lost as they can’t cope

the one that copes the best due to increased vascular supply, or increased FSH receptors is the dominant one selected for ovulation