5.2 The Menstrual Cycle

Question 1

define the menstrual cycle and what are the phases?

Answer 1

The monthly cyclical changes in secretion of female hormones with corresponding changes in ovaries, uterus and other sexual organs
Phases: Menstrual (before ovulation), proliferative(before) and secretary (after)

Question 2

Define the ovarian cycle and what are the phases?

Answer 2

Production of ovarian hormones with the release of a mature ovum
Phases: follicular (before ovulation) and luteal (after ovulation)

Question 3

Define endometrial cycle

Answer 3

Preparation for implantation: menses

Question 4

When do oestrogen and progesterone have their greatest effect on the endometrium

Answer 4

oestrogen: 1st half
progesterone: second half

Question 5

What is the role of oestrogen and the endometrium?

Answer 5

Causes proliferation of endometrial stroms and endometrial glands which later provide sustenance for the fertiized ovum

Question 6

What are the two roles of progesterone and the endometrium?

Answer 6

1. promotes secretory changes in endometrium: prepares the uterus for implantation, nourishes the fertilzed ovum
2. Inhibits FSH production which will prevent other follicles from developing

Question 7

What effects does oestrogen have on external female genitalia?

Answer 7

maturation at puberty and development of pubic hair

Question 8

What effects does oestrogen have on fallopian tubes?

Answer 8

increases number and motility of cilia

Question 9

What effects does oestrogen have on breasts?

Answer 9

growth of ducts and stroma, fat deposition

Question 10

What effects does oestrogen have on skeleton

Answer 10

inhibits bone breakdown, stimulates bone growth, epiphyseal fusion

Question 11

What effects does oestrogen have on skin

Answer 11

softer and more vascular

Question 12

What effects does progesterone have on the uterus?

Answer 12

decreases frequency/intensity of uterine contractions

Question 13

What effects does progesterone have on the fallopian tubes

Answer 13

promotes secretions necessary for nutrition and movement of fertilized ovum within the tube

Question 14

What effects does progesterone have on the breasts?

Answer 14

promotes development of lobules and alveoli causing swelling

Question 15

define menstruation

Answer 15

physiologic breakdown of late secretory endometrium due to spasm of spiral arterioles caused by dropping progesterone

Question 16

What are the risks of the combined pill?

Answer 16

Thrombosis, HTN, vascular events (stroke, MI)

Question 17

Benefits of combined pill

Answer 17

regular, less heavy periods, prevention of ovarian and endometrial cancer

Question 18

How does the progesterone only pill work?

Answer 18

Suppresses the LH surge and ovulation and creates a viscous and scant cervical mucous to deter sperm penetration

Question 19

what is an anovulatory cycle?

Answer 19

failure of ovum to be released

Question 20

What is the menstrual bleeding during an anovulatory cycle caused by?

Answer 20

inability of oestrogen to maintain endometrium growth