EOM: REPRODUCTION

Question 1

What is the name of the peptide
hormone which plays a major role in
both ovulation and the activity of the
interstitial cells of the testis?

Answer 1

Lutenising hormone - a surge makes Leydig cells produce testosterone

Question 2

Describe the actions of follicle-stimulating hormone.

Answer 2

• Women –> triggers maturation of ovarian follicles

- Men –> acts on Sertoli cells –> secrete inhibin to act on anterior pituitary

Question 3

Describe the actions of testosterone.

Answer 3

• Inhibits secretion of hormones by hypothalamus and anterior pituitary
• Released by Leydig cells - doesn’t modulate their activity

Question 4

Which peptide hormone is formed in the hypothalamus and is necessary for normal spermatogenesis?

Answer 4

Gonadotropin-releasing hormone

- Regulates production of FSH and LH

Question 5

What secretes inhibin?

Answer 5

Sertoli cells –> inhibit FSH and LH secretion via anterior pituitary

Question 6

Name possible causes of infertility.

Answer 6

• Anovulation
• Cervical mucus hostility (antibodies are produced and released into the mucus, killing sperm)
• Polycystic ovary syndrome

Question 7

Implantation happens after the blastocyst has hatched through:

Answer 7

Zone pellucida (glycoprotein layer)
- Embryo will then implant into decidua (progesterone-primed endometrium)

Question 8

What happens in the embryo after embryonic genome activation and before blastocyst formation?

Answer 8

Compaction

Question 9

After fertilisation, male and female nuclei are unified. What is this process called?

Answer 9

Syngamy

Question 10

Which genes confer self-renewal and pluripotency in embryonic stem cells?

Answer 10

OCT4 and Nanog (sliced upon differentiation)

Question 11

What is the best choice of treatment for a 36 year old man with 47XXY (=Kleinfelters) who is consistently azoospermia at semen analysis, but has a small number of sperm recovered by testicular biopsy. His 31 year old partner is of normal biology with patent fallopian tubes and has responded well to superovulation.

Answer 11

Intra-cytoplasmic sperm injection

• Sperm from testis is immotile so IVF would not be effective
• Want biological children so donor would not be best treatment
• Sperm cryopreservation would be ineffective as sperm as immotile