The Menstrual Cycle

Question 1

What is menstruation?

Answer 1

The periodic discharge of blood and tissue fluid due to the breakdown of the uterus lining; aka menstrual period
- 1 to 5 days
- During the follicular Phase

Question 2

What are the phases of the ovulation cycle?

Answer 2

1. Follicular
2. Ovulation
3. Luteal

Question 3

What are the changes in the uterine lining and endometrium for?

Answer 3

In preparation for a developing embryo in case the egg released at ovulation is fertilised.

Question 4

What happens in the first stage of the menstrual cycle while the follicle is maturing in the ovarian cycle?

Answer 4

1. Progesterone causes the endometrium of the uterus to become thicker and softer.
2. Increase in number of blood vessels/mucus-secreting glands

Question 5

What happens to the endometrium after ovulation?

Answer 5

It continues to thicken, and glands within it begin to secrete a watery mucus rich in glycogen.

Question 6

What happens 14 days after ovulation?

Answer 6

Blood from broken-down capillaries, mucous secretions and cell debris from the uterine lining are lost through the vagina.

Question 7

What is the follicular phase?

Answer 7

The preparation and maturation of a follicle.

Question 8

What does the follicular phase result in?

Answer 8

A Graafian follicle containing a secondary oocyte ready for release at ovulation.

Question 9

What does the anterior pituitary gland secrete in preparation for the next developing ova during menstruation?

Answer 9

FSH - causes follicle growth on ovary surface
- Many follicles begin to develop but only one will continue to maturity and be released at ovulation.

Question 10

What do the growing follicles release?

Answer 10

The growing follicles release oestrogen which signals the anterior pituitary gland to release luteinising hormone (LH)

Question 11

What happens during the ovulation stage?

Answer 11

The surge in LH causes the release of the secondary oocyte from the Graafian follicle.

Question 12

What happens to the secondary oocyte during the ovulation phase?

Answer 12

The secondary oocyte, now released into the fallopian tube, can then be fertilised by a spermatozoon which will form an ovum.

Question 13

What triggers the luteal phase?

Answer 13

The formation of the corpus luteum from the remnants of an unfertilised secondary oocyte/ ootid

Question 14

What happens during the luteal phase?

Answer 14

1. The corpus luteum produces progesterone and oestrogen.
2. Progesterone and Oestrogen cause a thickening of the endometrial lining which prepares the uterus for implantation of a potential fertilised egg.

Question 15

What happens to the corpus luteum if the egg is fertilised during the lateal phase?

Answer 15

It’s maintained and so are the progesterone and oestrogen levels. The endometrial lining is maintained and a period does not occur.

Question 16

What happens to the corpus luteum if the egg is not fertilised during the lateal phase?

Answer 16

1. It turns to scar tissue (corpus albicans), disintegrates and stops producing progesterone and oestrogen.
2. The endometrial lining is no longer maintained and begins to shed, triggering the next menstruation.