Unit 3- Reproductive hormones

Question 1

what are three layers of the adrenal cortex?

Answer 1

zona granulosa
zona fasciculata
zona reticularis

Question 2

what hormone does the zona granulosa produce?

Answer 2

mineralocorticoids (aldosterone)

Question 3

what hormone does the zona fasciculata produce?

Answer 3

glucocorticoids (cortisol)

Question 4

what hormone does the zona reticularis produce?

Answer 4

androgens

Question 5

what are androgens and give the five main ones

Answer 5

male sex hormones:

• testosterone
• dihydrotesterone (DHT)
• androstenedione
• androstenediol
• dehydroepiandrosterone (DHEA/ DHEA-S)

Question 6

describe the biosynthesis of steroid hormones

Answer 6

cholesterol - pregnenolone - progestagens - androgen (then converted into estrogen)/ cortisol/ aldosterone

Question 7

what enzyme does zona glomerulosa lack?

Answer 7

17-hydroxylase

Question 8

what enzyme does zona fasciculata and reticularis lack?

Answer 8

18-hydroxylase

Question 9

what condition will occur if deficiency in 21-hydroxylase?

Answer 9

sexual ambiguity (unable to produce cortisol/ aldosterone so excess production of androgens)

Question 10

what role does testerone produced in adrenal glands have in men and women?

Answer 10

small role in men as most from testes - responsible for secondary characteristics
primary source for women - converted into oestrogen -responsible for growth of pubic hair/ sex drive

Question 11

what happens if there is an overproduction of ACTH in men and women?

Answer 11

no effect in men

masculinisation in women: acne/ hirsitism (facial hair)/ breast shrinkage

Question 12

what does the first decline in DHEA signify?

Answer 12

adrenarche in boys due to development of zona reticularis - hit puberty

Question 13

what is the equivalent of adrenarche in girls?

Answer 13

menarche - menstrual cycle

Question 14

what are the two major functions of the testes? what hormones control these?

Answer 14

spermatogenesis
steroidogenesis
- controlled by FSH/ LH

Question 15

where does spermatogenesis occur? describe process

Answer 15

seminiferous tubules - spermatagonia produce sperm which enters epididymis for sperm maturation - gain motility and then to vas deferens to combine with prostate fluid to secrete as semen

Question 16

what role do sertoli cells have and what hormone stimulates them?

Answer 16

surround and faciliate spermatogonia by nourishing germ cells

• produce androgen binding proteins (SHBG) to keep high conc of androgens in testes and carries testosterone to epididymis
• stimulated by FSH

Question 17

what is the function of the three hormones secreted by sertoli cells?

Answer 17

inhibin - inhibits FSH
activin - stimulates FSH
follistatin - binds & deactivates activin

Question 18

what role do leydig cells have and what hormone stimulates them?

Answer 18

secrete testosterone

stimulated by LH

Question 19

what enzyme converts testosterone to DHT?

Answer 19

5 alpha reductase

Question 20

what enzyme convert testosterone to androstenedione?

Answer 20

17-ketoreductase

Question 21

what enzyme converts testosterone to estradiol (oestrogen)?

Answer 21

aromatase

Question 22

what is primary hypogonadism?

Answer 22

serum testosterone and sperm count below normal

FSH/LH above normal

Question 23

what is secondary hypogonadism?

Answer 23

indicates problem in pituitary gland/hypothalamus

Question 24

what is the effect of anabolic steroids on men?

Answer 24

partial hypogonadism - feminism - development of breasts but decrease in testicle size - no stimulation of sertoli cells

Question 25

what condition is an example of congenital primary hypogonadism?

Answer 25

Klinefelter's syndrome - extra copy of X chromosome - less chest hair/ wide lips/ small testicles

Question 26

what is the effect of 5-ARD deficiency?

Answer 26

inability to convert testosterone to DHT (which is more physiologically active) - look female at birth but develop small penis in later life (autosomal recessive)

Question 27

what is AIS?

Answer 27

androgen insensitivity syndrome - mutation of androgen receptor genetically male but genitals are female - body is insensitive to testosterone

Question 28

what are the two stages of the menstrual cycle?

Answer 28

``` follicular phase- menstrual phase (0-4)/ proliferative phase (4-14) luteal phase (14-28) ```

Question 29

explain hormonal changes and uterine changes that occur in the follicular phase

Answer 29

menstrual phase: decrease in progesterone - breakdown of endometrial lining = bleeding proliferative phase: increase in oestrogen = endometrial proliferation - follicles develop and secrete more oestrogen/ development of uterine glands at day 14; surge in oestrogen - causes surge in FSH and LH- LH surge stimulates ovulation

Question 30

what process occurs in the luteal phase?

Answer 30

formation of corpus luteum - follicles undergo luteinization - collapse into space behind - formation of blood clot forms core surrounded by collapsed layer of granulosa cells in a thecal cells - enlarge and develop lipid inclusions

Question 31

what is the effects of the corpus luteum?

Answer 31

contain large amounts of golgi apparatus, endoplasmic reticulum and mitochondria - secrete progesterone = build up of stromal cells/ stimulate uterine glands to secrete uterine milk (high in protein and glycogen) to maintain endometrium - secrete oestrogen - negative feedback to decrease FSH/LH

Question 32

what will happen if ovum is not fertilised?

Answer 32

corpus luteum degenerated by luteolysis whoch causes decrease in levels of progesterone and oestrogen - levels of FSH/LH increase in preparation for next menstrual cycle

Question 33

which hormones will increase if ovum is fertilised?

Answer 33

following implantation of egg, hCG, progesterone and oestrogen levels increase

Question 34

what is the effect of hCG?

Answer 34

maintains corpus luteum in ovary so that it continues to secrete progesterone - stimulates growth of endometrium eventually form the placenta. once placenta developed levels of hCG decrease after 8 weeks

Question 35

what are the other effects of progesterone apart from growth of endometrium?

Answer 35

- increases blood flow to uterus - stimulation of uterine glands - stimulates production of decidua - supports attachment of placenta

Question 36

what are the effects of oestrogen during pregnance?

Answer 36

- growth of breasts / lactation - growth of placenta - development of fetal organs

Question 37

what hormone is produced prior to parturition?

Answer 37

relaxin - produced by corpus luteum and placenta | - relaxes joints/ ligaments in pelvis which causes ripening of cervix and dilation of blood vessels

Question 38

what hormones stimulate contractions?

Answer 38

oestrogen causes contraction - stimulates uterus to produce prostaglandins which decreases level of progesterone and initiate labour oxytocin - stimulated by pressure of baby on cervix/ pelvic floor - causes powerful contractions

Question 39

what is the effect of decreased progesterone levels?

Answer 39

braxton hicks - increased myometrial excitability

Question 40

what is the function of thecal and granulosa cells?

Answer 40

theca - stimulated by LH - converts cholesterol to androgens | granulosa - stimulated by FSH - produces aromatase to convert androgens to oestrogen