Hormones of the Reproductive System – non-pregnancy

Question 1

5 components of the male reproductive system

Answer 1

Testes
Epididymis
Vas deferens
Prostate and seminal vesicles
Penis

Question 2

6 components of the female reproductive system

Answer 2

Ovaries 
Uterine tubes
Uterus
Vagina
Vulva 
Breasts

Question 3

What are the two gonadotrophins

Answer 3

Follicle-stimulating hormone

Luteinising hormone

Question 4

How is gamete production occur via hormones

Answer 4

Internal an external stimulus causes the hypothalamus to relase kisspeptin, wihch stimulates the release of GnRH
GnRH causes the Ant. P to release LH and FSH
LH acts on endocrine cells to release steroid and peptide hormones, which cause gamete production
FSH stimulates gamete produce directly
(LH can also stimulate gamete production directly in females only)

Question 5

Explain the negative feedback of hormonal control of gamete production

Answer 5

Steroid and peptide hormones act on adenohypophysis and hypothalamus o reduce the secretion of LH, FSH, GnRH and
kisspeptin

Question 6

where is the site of sperm production

Answer 6

Tough outer fibrous capsule that encloses the seminiferous tubules of the testes

Question 7

What lies inbetween the tubules of the testes

Answer 7

Interstitial tissue

Question 8

What does interstitial tissue contain

Answer 8

testosterone-producing interstitial cells of Leydig

Question 9

What becomes the vas deferens

Answer 9

Seminiferous tubules leave the testis and join the epididymis, eventually becoming he vas deferens

Question 10

What is the vas deferens

Answer 10

duct which passes into the abdomen and eventually empties into the urethra

Question 11

What are Sertoli cells

Answer 11

Located in the seminiferous tubules

Produce and secrete proteins that range from hormones (inhibin and activin) to growth factors, enzymes and ABP

Question 12

What is the function of inhibin and activin

Answer 12

inhibin - inhibits FSH secretion

Activin - stimulates FSH secretions

Question 13

What do androgen-binding proteins do

Answer 13

ABP binds to testosterone which becomes less lipophilic and cannot diffuse out of seminiferous tubule lumen

Question 14

What are Leydig cells

Answer 14

Secrete testosterone

Also convert some testosterone to oestradiol

Question 15

When are Leydig cells active

Answer 15

Active in the foetus (since testosterone is needed to direct development of male characteristics)
Becomes inactive at birth, then reactivates during puberty

Question 16

Explain the hormonal control of spermatogenesis

Answer 16

Hypothalamic GnRH promotes release of FSH and LH from adenohypophysis
FSH targets Sertoli cells
This stimulates synthesis of paracrine molecules needed for spermatogenesis
Stimulates ABP and inhibin production
LH targets Leydig cells, which produce testosterone
Sertoli cells mediate testosterone action

Question 17

What are androgens

Answer 17

Precursors of oestrogen; active during puberty

Question 18

Explain hormonal regulation of the female RS

Answer 18

GnRH is released from hypothalamus and causes the adenohypophysis to release LH+FSH
LH and FSH act on the ovary to release oestrogen and progesterone
Oestrogen causes the growth of reproductive organs and endometrium
Progesterone causes the maintenance and secretion of endometrium

Question 19

3 phases of the ovarian cycle

Answer 19

Follicular phase - follicular growth in the ovary
Ovulation - one or more follicles have ripened; ovary releases oocyte
Luteal phase - transformation of ruptured follicle into corpus luteum, which secretes hormones that continue preparations for pregnancy, if pregnancy doesn’t occur than corpus luteum ceases to function

Question 20

Explain the phases of the uterine cycle

Answer 20

Menses - corresponds to the follicular phase, results in menstrual bleeding form h uterus
Proliferative phase - endometrium adds a new layer of cells in anticipation of pregnancy
Secretory phase hormones from corpus luteum convert the thickened endometrium into a secretory structure ; if pregnancy doesn’t occur then superficial layer of endometrium are lost

Question 21

Explain what happens in the early follicular phase in relation to hormones

Answer 21

Gonadotrophin (FSH and LH) secretion from AP increases
FSH causes tertiary follicles to begin to mature
As these grow, their cells start to produce steroid hormones
Increasing levels of oestrogens lead to inhibition of FSH and LH secretion, preventing development of additional follicles in the same cycle
Oestrogen stimulates granulosa cells to produce additional oestrogen, follicles can continue oestrogen production even though FSH and LH levels decrease

Question 22

Explain what happens in mid to late follicular phase regarding hormones

Answer 22

Inhibin and progesterone begin to be secreted
Oestrogen levels remain high leading to enhanced pituitary responsiveness to GnRH
LH secretion spikes, which is essential for final steps of oocyte maturation

Question 23

Explain what occurs hormonally during early to mid luteal phase

Answer 23

Luteal cells form and secrete hormones
Corpus luteum produces steadily increasing amounts of progesterone, oestrogen and inhibin
Progesterone is dominant hormone
Progesterone and oestrogen exert negative feedback on hypothalamus and AP - secretions of gonadotrophins is stopped

Question 24

What occurs hormonally in late luteal phase

Answer 24

If pregnancy does not occur, the corpus luteum undergoes apoptosis
As the cells degenerate, progesterone and oestrogen levels decrease
Removing the negative feedback on hypothalamus and AP leading to FSH and LH secretion