Physiology: Reproductive Physiology

Question 1

What is the action of FSH in females?

Answer 1

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

Question 2

What is the action of FSH in males?

Answer 2

Cause the testes to produce sperm (spermatogenesis)

Question 3

Describe the secretion of GnRH in females

Answer 3

The frequency of the pulses varies during the menstrual cycle to stimulate secretion LH (high frequency) or FSH (low frequency) as appropriate

Question 4

Describe the epithelium of the cervix

Answer 4

Columnar epithelial cells, site of mucus production

Question 5

Describe the structure of the extratubular compartment of the testes

Answer 5

Interstitial and intravascular component

Question 6

Name the two phases of the menstrual cycle

Answer 6

Follicular phase and luteal phase

Question 7

Name the cells in the seminiferous tubules which produce mature sperm and inhibin in response to FSH

Answer 7

Sertoli cells

Question 8

What hormone do home ovulation kits use to predict ovulation?

Answer 8

LH

Question 9

Name the hormone responsible for the release of FSH and LH from the anterior pituitary

Answer 9

Gonadotrophin releasing hormone (GnRH)

Question 10

What is the action of LH in females?

Answer 10

Causes ovulation and causes progesterone production by the corpus luteum

Question 11

What is dihydrotestosterone?

Answer 11

Testosterone which reaches other target tissues is converted to dihydrotestosterone (highly active form) and oestradiol - responsible for enlargement of male sex organs, development of secondary sexual characteristics and anabolism

Question 12

Name the hormone secreted by the corpus luteum (placenta in pregnancy) which inhibits LH secretion - pro-gestation

Answer 12

Progesterone

Question 13

Describe the hormonal events in pregnancy

Answer 13

Follicle produces oestradiol

If a fertilised ovum emplants in the corpus luteum, progesterone will be released

If implantation occurs, the emplanted embryo will produce HCG (pregnancy test)

The placenta will produce human placental lactogen (hPL), placental progesterone and placental oestrogens

During pregnancy, the pituitary produces prolactin (lactogen)

Question 14

Describe the structure of the intratubular compartment of the testes

Answer 14

Basal and adluminal compartment, sertoli cells and germ cells (at different stages of development)

Question 15

What is the action of LH in males?

Answer 15

Causes the testes to secrete testosterone

Question 16

90% of testosterone is taken up by ______ ____ where it stimulates spermatogenesis

Answer 16

Sertoli cells

Question 17

What is Spinnbarkeit?

Answer 17

Describes the property of cervical mucus which changes in response to high levels of oestrogen around the time of ovulation - it becomes thin and slippery, and very stretchy

Question 18

GnHR is released by the hypothalamus in a _______ manner

Answer 18

Pulsatile

Question 19

Describe the structure of a follicle

Answer 19

Consists of an oocyte surrounded by follicular cells

Question 20

Describe the hormonal regulation of the menstrual cycle

Answer 20

1. FSH stimulates growth of ovarian follicles
2. Oestrogen levels rise which lowers FSH levels (negative feedback)
3. Once oestrogen reaches a certain concentration it exerts positive feedback regulation resulting in an increase in FSH levels and the LH ‘surge’
4. LH surge leads to ovulation, corpus luteum formation and progesterone production
5. Increasing progesterone decreases LH secretion by influencing GnRH pulsatility

Question 21

Name the hormones that:

Increase the thickness of the endometrium

Regulate LH surge

Reduce vaginal pH through increase in lactic acid production

Decrease viscosity of cervical mucus to facilitate sperm penetration

Answer 21

Oestrogens

Question 22

What is the function of the blood-testes barrier?

Answer 22

Restricts contact between postmitotic germ cells and the immune system to prevent rejection of spermatogenic cells (form after immune tolerance)

Question 23

Name the cells of the testes which produce testosterone in response to LH

Answer 23

Leydig cells

Question 24

Basal body temperature shifts by 0.2-0.4 ℃ following ________

Answer 24

Ovulation

Question 25

Describe the stroma of the cervix

Answer 25

Fibroblast cells surrounded by a collagen matrix, regulates the rigidity of the cervical wall

Question 26

Describe the secretion of GnRH in males

Answer 26

Secreted in pulses at a constant frequency

Question 27

Endometrium thickens under the influence of oestrogen and becomes a secretory tissue under the influence of __________

Answer 27

Progesterone

Question 28

How is GnRH pulsatility regulated?

Answer 28

Oestrogen and progesterone/testosterone act indirectly via kisspeptin neurones which then influence the hypothalamus

Question 29

What is the function of inhibin?

Answer 29

In males, feeds back to the pituitary to decrease FSH secretion