Menstrual Cycle Physiology

Question 1

Which cells in the ovarian follicle produce androgens?

Answer 1

Theca (interna) cells

Question 2

Which cells int he ovarian follicle convert androgens to oestrogen?

Answer 2

Granulosa cells

Question 3

Which enzyme is responsible for converting androgens to oestrogens?

Answer 3

Aromatase

Question 4

What is the most potent oestrogen produced by the ovary?

Answer 4

Oestradiol

Question 5

What is the importance of oestrogen in the development of a female?

Answer 5

Development of secondary sexual characteristics.

Question 6

What is the name of the part of the cycle spanning day 1-12?

Answer 6

Follicular Hhase

Question 7

What pivotal point occurs between days 12-14?

Answer 7

Ovulation

Question 8

What is the name of the part of the cycle spanning day 15-28?

Answer 8

Luteal Phase

Question 9

What process is the onset of the follicular phase (and the whole cycle)?

Answer 9

Menstruation

Question 10

What hormone starts to increase as the follicular phase begins?

Answer 10

GnRH - from hypothalamus, causing release of FSH and LH from the pituitary gland.

Question 11

What does Leutinising Hormone (LH) do?

Answer 11

Stimulates theca cells of the follicle to produce androgens.

Question 12

What does Follicle Stimulating Hormone (FSH) do?

Answer 12

Stimulates the granulosa cells to convert androgens to oestrogen.
Causes maturation of follicles until a Graffian follicle emerges.

Question 13

Rising levels of oestrogen in the follicular phase inhibit which hormone?

Answer 13

FSH

Question 14

A peak of oestrogen triggers a surge in which hormone? What is the result?

Answer 14

LH - resulting in ovulation.

Question 15

What effect does LH have on the follicle after ovulation?

Answer 15

Stimulates development into the corpus luteum.

Question 16

What is released by the corpus luteum?

Answer 16

Progesterone

Question 17

What is the effect of progesterone in the Luteal phase?

Answer 17

Induction of secretory activity in the endometrium, increasing thickness.

Question 18

Besides preparing the endometrium for implantation, what other effect does progesterone have?

Answer 18

Increase in basal body temperature
Increased thickness of cervical mucus
Glandular development of breasts
Inhibiton of FSH and LH (in high levels)

Question 19

If fertilisation does not occur, what happens to the corpus luteum?

Answer 19

Degeneration, dropping progesterone levels.

Question 20

What is the result of the drop in progesterone following the degeneration of the corpus luteum?

Answer 20

Vasospasm in arterioles of the endometrium, causing necrosis and bleeding a.k.a. menstruation.

Question 21

Following the drop in progesterone levels, what hormones are no longer inhibited?

Answer 21

LH and FSH - the cycle begins again.