The physiology of the menstrual cycle

Question 1

What is the the duration of a normal menstrual cycle?
what is the average

Answer 1

21- 35 days
28days

Question 2

What is menstruation?

Answer 2

Menstruation is the periodic discharge of blood, mucus and uterine cellular debris at cyclic intervals from menarche to menopause.

Question 3

At what age do we expect menarche?

Answer 3

10 to 16
Average 13

Question 4

how much blood loss is expected during the mensturating period?

Answer 4

less than 80mls

Question 5

What does blood from one’s menses not coagulate?

Answer 5

due to the secretion of fibrinolysin enzyme (plasmin) secreted by the endometrium

Question 6

Define the following ;
Dysmenorrhea
Molimina
Mittleschmerz

Answer 6

Dysmenorrhea-it is the lower abdominal pain shortly before or during menstruation in heh absence of pathologic findings that account for those symptoms

Molimina-mild symptoms that occur before menstruation occurs(headache, acne, bloating, negative moods, cramps, fatigue and tenderness of breast)

Mittelschmerz-physiological preovulatory pain in female individuals of reproductive age

Question 7

What is the effect of estrogen on the endometrium?

Answer 7

-stimulates the repair of the endometrium.

Question 8

What is the effect of progesterone on the endometrium?

Answer 8

Stimulates thickening of and maintains endometrium

Question 9

What releases hCG? And what is the role of it?

Answer 9

-Embryo(if pregnant)
-Stimulates the production of progesterone.

Question 10

What are the phases of the Ovarian Cycle?

Answer 10

1.Follicular
2.Ovulatory phase
3.Luteal phase

Question 11

Describe what occurs during the follicular phase of the ovarian cycle?

Question 12

Which hormone causes the ovulatory phase?

Answer 12

Lutenizing hormone

Question 13

Describe the vents that occur during the luteal phase?

Question 14

What is the function of inhibin?

Answer 14

It inhibits the release of FSH

Question 15

What are the phases of the uterine cycle?

Answer 15

1.Menstrual and Proliferative phase
2.The secretory phase

Question 16

Which layer of the endometrium is sloughed off during menstruation?

Answer 16

Stratum functionale

Question 17

What causes shedding of the endometrium during the menstrual phase?

Answer 17

-Low levels of progesterone and estrogen results in the spiral arteries collapsing. endometrial lining becomes ischemic and as result ruptures and sloughs off causing the menstrual bleed.

Question 18

How long does mesntrual bleeding take to occur?

Answer 18

2-7 days

Question 19

Describe what occurs during the proliferative phase.

Answer 19

Estrogen are high and endometrium begins to regenerate
1. Thickness of endometrium 3-4mm
2. Glands are increased in number and length, but remain tubular.
3. The stroma cells proliferate and show mitosis.
4. Vascularity is increased, the spinal arteries increased in length and traverse the whole endometrium

Cervical changes occur that make it more hospitable for sperm.

Question 20

Describe the Secretory phase ?

Answer 20

The corpus luteum (granulosa cells) is producing progesterone.
Progesterone maintains the lining of the endometrium.
Spiral arteries grow longer and uterine glands secrete more mucus