Endocrine Regulation of male and female reproduction

Question 1

What is GnRH?

Answer 1

Gonadotrophin releasing hormone

Question 2

How and What produces GnRH?

Answer 2

Produced in pulses by hypothalamus

Question 3

What gland does GnRH diffuse to and what does it release?

Answer 3

Pituitary and releases gonadotropins

Question 4

What hormones do gonadotropins consist of?

Answer 4

LH - leutinising hormone

FSH - follicle stimulating hormone

Question 5

When are gonodotropin reserves replenished?

Answer 5

Between pulses of GnRH

Question 6

What does overstimulation with GnRH lead to?

Answer 6

Gonadotropin depletion and defiency

Question 7

What does understimulation with GnRH lead to?

Answer 7

Gonadotropin production and defiency

Question 8

What cells does FSH act on?

Answer 8

Only sertoli cells

Question 9

How does FSH work?

Answer 9

Produced ABP for transport of testosterone around blood

Question 10

What is ABP?

Answer 10

Androgen binding protein

Question 11

What cells does LH act on?

Answer 11

Leydig cells

Question 12

How does LH work?

Answer 12

Leydig produce testosterone

Question 13

What does testosterone act on?

Answer 13

Germ cells directly but bone, skin and hair

Question 14

What is Testosterone converted to?

Answer 14

Dihydrotesterone DHT

Question 15

What does DHT effect?

Answer 15

Prostate and oestradial

Question 16

Why is DHT important?

Answer 16

Epiphysial closure - height and repro system - fertility

Question 17

What is FSH negatively regulated by?

Answer 17

Inhibin at pituitary

Question 18

What is FSH positively regulated by?

Answer 18

Activin and follistatin

Question 19

What is LH negatively regulated by?

Answer 19

Testosterone @ pituitary and hypothalamus

Question 20

What are the 4 phases of the ovarian cycle?

Answer 20

Follicular phase, ovulatory phase, luteal phase, menstruation

Question 21

How is the ovarian cycle regulated?

Answer 21

By gonadotrophin of LH and FSH at pulsatile release due to control of GnRH

Question 22

What are the 2 main steroid hormones in the ovarian cycle?

Answer 22

Oestrogen and progresterone

Question 23

What hormone acts on the primary and secondary follicles and what does it do?

Answer 23

FSH and causes follicular growth

Question 24

What does FSH due?

Answer 24

Promote oestradial secretion from follicle

Question 25

What hormones produced negative feedback on FSH?

Answer 25

Oestrogen (oestradial) and Inhibin

Question 26

What hormone decreases as oestrogen rises?

Answer 26

FSH

Question 27

Why is cell cycle arrested at phase II of metaphase?

Answer 27

Oocyte is fertilized

Question 28

What happens to oestradial on day 12?

Answer 28

Switches to positive feedback as LH rises from pituitary

Question 29

What happens to the tertiary follicle at luteal phase?

Answer 29

Collapses and gran cells leutines and invade endocrine structure

Question 30

What endocrine structure do gran cells luteinise?

Answer 30

Corpus luteum

Question 31

What does the Corpus luteum secrete?

Answer 31

Oestradial and progresterone

Question 32

What does the corpus luteum maintain?

Answer 32

Endometrium

Question 33

What does the corpus luteum supress?

Answer 33

LH and FSH

Question 34

What happens in the late luteal phase?

Answer 34

Corpus luteum involutes and Oestradial and progresterine fall, loss of negative feedback and menstruation occurs

Question 35

How does the corpus luteum involute?

Answer 35

Invaded by macrophages

Question 36

What hormone rises once menstruation occurs?

Answer 36

FSH

Question 37

If the ovum implants what does the uterus secrete?

Answer 37

Chrionic gonadotrophin (hCG)

Question 38

What does hCG do?

Answer 38

Maintains corpus luteum

Question 39

What effects does Oestrogen do?

Answer 39

Maintains bone mass, CNS, vasculature on both sexes, in females it effects fat distribution, promotes insulin, thrombosis and lipid metabolism

Question 40

What are the other roles of progesterone?

Answer 40

Causes body temp to rise, change to thick cervical mucus, down regulates oestrogen and negative feedback

Question 41

What can menopause do to a female in 40s 50s?

Answer 41

Mood changes, loss of libido and hot flushes

Question 42

How is menopause caused?

Answer 42

Decline in ovarian follicle numbers and reduced response to gonadotrophins and lpss of oestrogen

Question 43

What hormones increase with menopause?

Answer 43

LH, FSH

Question 44

What is there an increased risk of in menopause?

Answer 44

Reduce vaginal lubrication due to rise of PH, Vasomotor changes cause hot flushes, osteoporosis