The menstrual cycle

Question 1

What is the first phase of the menstrual cycle?

Answer 1

Follicular phase

Question 2

What is another name for the follicular phase of menstruation?

Answer 2

Proliferative

Question 3

Follicle maturation is brought about by what hormone?

Answer 3

FSH

Question 4

The FSH has what effect upon this cohort of follicles?

Answer 4

Granulosa cell proliferation + aromatase activity

Question 5

Which cells produce androgen precursors?

Answer 5

Theca cells

Question 6

Which cells convert androgens to oestrogen?

Answer 6

Granulosa cells

Question 7

At what point does the Graafian follicle become apparent?

Answer 7

Days 5-7

Question 8

What is the length of a ‘normal’ cycle?

Answer 8

25-35 days

Question 9

When is menarche considered delayed?

Answer 9

Should it not occur until beyond 16 years

Question 10

What are the causes of delayed menarche?

Answer 10

1. Imperforate hymen (causing haematocolpos)
2. Vaginal atrophy
3. Testicular feminisation
4. Pituitary/hypothalamus failure
5. Gonadal dysgenesis
6. Turner’s syndrome

Question 11

What brings about suppression of FSH in the follicular phase?

Answer 11

High oestrogen + inhibin levels. FSH suppression prevents further follicular recruitment

Question 12

When does the LH surge occur?

Answer 12

During the ovulatory phase

Question 13

What is the result of the LH surge?

Answer 13

Ovulation - release of the oocyte from the Graafian follicle

Question 14

In what phase is the corpus luteum formed?

Answer 14

The luteal phase

Question 15

What occurs following the luteal phase?

Answer 15

The menstrual (ischaemic) phase

Question 16

What is the mechanism of menstruation?

Answer 16

Spasm of the spiral arteries - contraction being caused by PGE, and dilation by PGF - endometrial shedding and fibrinolysis splits fibrinogen and in the main will prevent clotting