Lecture 7: Physiology of the Female Reproductive System

Question 1

When does gamete production first begin?

Answer 1

During foetal development

Question 2

Primary oocytes are arrested at?

Answer 2

prophase 1 of meiosis 1

Question 3

When does gamete production begin again?

Answer 3

During puberty, where meiosis 1 is complete prior to ovulation (secondary oocyte and first polar body) and meiosis 2 is completed after fertilization (having been arrested in metaphase 2)

Question 4

What are the gonadotropins stimulated by GnRH?

Answer 4

LH and FSH

Question 5

What are the steroid hormones and glycoprotein hormones produced by LH and FSH stimulation to the ovary?

Answer 5

Steroid hormones – can’t be stored, must be made on demand:
o	Progesterone
o	estrogen (17β-estradiol)
o	Androgens 
	Testosterone
	Androstenedione

Glycoprotein hormones – can be made in advance and stored
o Inhibin A and inhibin B (produced at different times of the cycle)

Question 6

What is independent of FSH and LH?

Answer 6

The process from primordial follicle to secondary follicle

Question 7

What needs to happen before a follicle can become a Graafian follicle?

Answer 7

It needs to express FSH and LH sensitivity

Question 8

What is a corpus albicans?

Answer 8

A degenerated corpus luteum as a consequence of no fertilization

Question 9

What happens in the late luteal to early follicular phase?

Answer 9

• Early rise in FSH leads to expansion of granulosa cells
• Theca cells stimulated by LH to produce Progesterone and Adrenostenedione (converted to oestrogen in granulosa cells)
• oestrogen has paracrine action on theca cells and autocrine action on granulosa cells
• Inhibin B produced at the same rate of oestrogen and supresses FSH (follicular selection)

Question 10

What happens in the early follicular phase?

Answer 10

• Oestrogen suppresses the ARC leading to less GnRH and FSH and LH
• Decline in FSH due to Inhibin B and oestrogen action (LH storage)

Question 11

What happens in the Mid-Late Follicular Phase?

Answer 11

• Surge in estradiol levels two days before ovulation because it is greater than 200pg/ml
• AVPV stimulated leading to LH and FSH surge

Question 12

How long does the oocyte last?

Answer 12

12-24 hours

Question 13

What happens during the early luteal phase? Which Inhibin dominates?

Answer 13

• Corpus luteum formed
• Huge production of progesterone and oestrogen
• Inhibin A is produced
• Suppression of ARC and anterior pituitary due to oestrogen

Question 14

What happens during the mid-luteal phase?

What is there a delay in?

Answer 14

• Accumulation of cholesterol (stimulated by LH surge)

- Delay (6-8 days) between the surge of LH and the synthesis of oestrogen and progesterone?

Question 15

What happens during the late luteal phase?

Answer 15

-Negative feedback supresses FSH and LH until corpus luteum cannot produce hormones enough leading do a rise in FSH and LH (less negative feedback) as GnRH increases.

Question 16

What are the three stages of the uterine cycle?

Answer 16

1. Menses
2. Proliferative Phase
3. Secretory Phase