The menstrual cycle

Question 1

What is the menstrual cycle?

Answer 1

The monthly process of the maturation of the oocyte

Question 2

What is Menarche? (1)

Answer 2

The onset of periods

Question 3

What factor can influence the Menarche? (1)

Answer 3

High body fat percentage - higher levels of Leptin

Question 4

What phases does the menstrual cycle consist of? (2)

Answer 4

The follicular/ proliferative phase (postmenstrual)
The luteal/ secretory phase (premenstrual)

Question 5

What hormone triggers the onset of periods?

Answer 5

Leptin - a regulatory hormone of appetite and energy metabolism)

Question 6

What is the function of the menstrual cycle?

Answer 6

To allow reproduction.

Question 7

How does Leptin trigger Menarche? (3)

Answer 7

Leptin hormone promotes the stimulation of the hypothalamus = release of GnRH (Gonadatrophin) = promotes release of FSH, LH & Estradiol = ovulation triggered

Question 8

What is menstruation?

Answer 8

The cyclical activity involving partial shedding of the endometrium.

Question 9

What is amenorrhea?

Answer 9

The absence of periods.

Question 10

What is dysmenorrhea?

Answer 10

Painful periods.

Question 11

What is menopause? (1)

Answer 11

End/ stopping of the menstrual cycle

Question 12

What is menorrhagia?

Answer 12

Heavy periods.

Question 13

Roughly what age does menopause occur? (1)

Answer 13

Between the ages 52-55

Question 14

When does the typical menstrual cycle occur?

Answer 14

Usually, every 21-35 days with an average of 28 days.

Question 15

When does ovulation take place?

Answer 15

On day 14 of the menstrual cycle.

Question 16

What happens to the endometrium during menstruation? (1)

Answer 16

The stratum functionalis is discharged through the vagina

Question 17

On average, how many days will a woman bleed during their menstrual cycle?

Answer 17

5 days

Question 18

What is the typical volume of blood loss during menstruation?

Answer 18

30-40ml

Question 19

What is the volume of blood loss that describes menorrhagia?

Answer 19

80ml

Question 20

What is menstrual loss comprised of?

Answer 20

80% blood
less than 25% endometrial tissue fluid and mucus

Question 21

What does a primordial follicle consist of? (1)

Answer 21

An oocyte and a single cell layer of granulosa cells

Question 22

Why does menstrual loss contain minimum fibrinogen?

Answer 22

This is a clotting agent that prevents the blood from clotting.

Question 23

Where is gonadotrophin released?

Answer 23

The pituitary gland.

Question 24

What hormone increases as the granulosa cells multiply?

Answer 24

Oestrogen.

Question 25

What is ovulation?

Answer 25

The process in which the mature oocyte is released from the ovary and taken into the uterine tube.

Question 26

What are the four main hormones involved in the menstrual cycle? (4)

Answer 26

Follicle stimulating hormone (FSH) Luteinising hormone (LH) Oestrogen Progesterone

Question 27

Which phase of the menstrual cycle is always 14 days long?

Answer 27

Luteal phase.

Question 28

What is the role of oestrogen during the menstrual cycle? (3)

Answer 28

To stimulate the uterine blood vessels. To aid the development of the endometrium Thinnen cervical mucus to allow sperm to reach egg.

Question 29

What happens to LH and FSH when oestrogen rises?

Answer 29

They are suppressed.

Question 30

What hormone does the corpus luteum secrete high levels of?

Answer 30

Progesterone.

Question 31

If fertilisation takes place, what hormone does the embryo release?

Answer 31

Human chorionic gonadotrophin (HCG)

Question 32

What hormone maintains the corpus luteum?

Answer 32

Human chorionic gonadotrophin (HCG)

Question 33

At the start of follicular development, what layer does the cells divide into?

Answer 33

The stromal layer which surrounds the granulosa cells.

Question 34

What cells forms with the continuum of follicular development?

Answer 34

The theca cells.

Question 35

Where do the theca cells lie?

Answer 35

Between the granulosa and the stromal cells.

Question 36

What is the oocyte surrounded by?

Answer 36

The zona pellucida.

Question 37

What develops from the primordial follicle?

Answer 37

The follicular antrum.

Question 38

Outline the follicular development

Answer 38

1. Primordial follicle - an oocyte and a single layer of cells 2. Layer of cells begin to devide and create further layers - over time becoming the granulosa cells, the theca interna and externa and the stromal cells. The space between the oocyte and the granulosa cells is called the sons pellucida. 3. The follicular antrum develops and is filled with follicular fluid 4. The oocyte is mature - suspended in follicular fluid and attached to the granulosa cell layer by a stalk 5. Ovulation occurs - Follicle ruptures to release the ovum - triggers start of luteal phase

Question 39

What is the follicular antrum filled with?

Answer 39

Follicular fluid.

Question 40

What is suspended in the follicular fluid of the follicular antrum?

Answer 40

A mature oocyte.

Question 41

What is the mature oocyte attached to in the follicular antrum?

Answer 41

The granulosa cell layer via a stalk.

Question 42

What happens at the point of ovulation?

Answer 42

The follicle ruptures to release the oocyte, the corpus luteum is formed.