Reproductive physiology

Question 1

Which reproductive hormone does the hypothalamus produce?

Answer 1

Gonadotropin releasing hormone (GnRH)

Question 2

Which reproductive hormones does the pituitary produce?

Answer 2

• Gonadotrophins
  
  • FSH (follicle stimulating hormone)
  • LH (Leutinising hormone)

Question 3

Which female reproductive hormones do the ovaries produce?

Answer 3

• Steroid hormone
  
  • Oestrogen
  • Progesterone

Question 4

What are the three stages of the menustrual cycle?

Answer 4

• Follicular
• Ovualtory
• Luteal

Question 5

What is FSH (follicular stimulating hormone) responsible for in females?

Answer 5

Responsible for starting follicle development and causing the level of oestrogen to rise.

Question 6

What is LH (leutenising hormone) responsible for in females?

Answer 6

Aids in egg maturation and provides the hormonal trigger to cause ovulation.

Question 7

Describe the follicular phase of the cycle.

Answer 7

FSH and LH stimulate the growth of several ovarian follicles, each containing one egg. One follicle will soon begin to grow faster than others. This is called the dominant follicle. As the follicle grows, blood levels of oestrogen rise significantly. This increase in oestrogen begins to inhibit the secretion of FSH. The fall in FSH allows smaller follicles to die off.

Question 8

Describe ovulation.

Answer 8

When the level of oestrogen is sufficiently high, it produces a sudden release of LH. This LH peak triggers the final maturation of the egg and follicular collapse with egg extrusion. Ovulation takes place 36 hours after the onset of the LH surge.

Question 9

What happens to the cells left behind in the ovarian follicle after ovulation?

Answer 9

The cells in the ovarian follicle that are left behind after ovulation undergo a transformation and become the corpus luteum. In addition to oestrogen, they now produce high amounts of progesterone to prepare the lining of the uterus for implantation.

Question 10

Describe the luteal phase.

Answer 10

Under the influence of progesterone, the uterus begins to create a highly vascularized bed for a fertilised egg. If a pregnancy occurs, the corpus luteum produces progesterone until about 10 weeks gestation. If no embryo implants, the circulating levels of hormone decline with the degeneration of the corpus luteum. The endometrium is shed leading to bleeding.

Question 11

Describe oogenesis.

Answer 11

Puberty onwards a group of primary oocytes are hormone responsive and each month one develops into secondary oocyte capable of fertilisation (ovarian cycle).

Question 12

What reproductive hormone is produced by the testes?

Answer 12

Testosterone

Question 13

Function of germ cells in the testis?

Answer 13

Spermatogenesis

Question 14

Function of sertoli cells in the testis?

Answer 14

• Support sperm producing cells
• Produce inhibin.

Question 15

Function of interstitial cells of Leydig.

Answer 15

Produce testosterone.

Question 16

What is FSH (follicular stimulating hormone) responsible for in males?

Answer 16

Stimulates the Sertoli cells.

Question 17

What is LH (leutenising hormone) responsible for in males?

Answer 17

Stimulates the interstitial cells of Leydig.

Question 18

What does testosterone do in males?

Answer 18

Stimulates spermatogenesis and is responsible for the secondary sexual characteristics that develop in the male during adolescence.

Question 19

What is the function of inhibin?

Answer 19

The Sertoli cells produce the hormone inhibin into the blood when the sperm count is too high. This inhibits the release of GnRH and FSH, which will cause spermatogenesis to slow down.

Question 20

Where do sperm mature?

Answer 20

In seminiferous tubules that are coiled inside the testes.

Question 21

Where do sperm go when they have developed flagella and are nearly mature?

Answer 21

The epididymis.

Question 22

The bulk of semen comes from which accessory glands?

Answer 22

• The seminal vesicles
• The prostate gland
• The bulbourethral gland

Question 23

What produces b-hCG?

Answer 23

Trophoblast cells on outside of fertilised egg.

Question 24

What is the function of human chorionic gonadotropin?

Answer 24

Function is to stimulate corpus luteum to produce progestogen, which stops decidua from shedding.