Normal Menstrual Cycle

Question 1

length of average menstrual cycle

Answer 1

28 days

Question 2

what day of the cycle does ovulation usually occur

Answer 2

day 14

Question 3

where is GnRh released from and what does it act on

Answer 3

Hypothalamus

Anterior pituitary

Question 4

GnRh causes the release of what hormones from the pituitary

Answer 4

LH

FSH

Question 5

What effect does FSH have on the ovary

Answer 5

Stimulates development of the follicle

Secretion of oestrogen + Inhibin

Question 6

What effect does LH have on the ovary

Answer 6

Production of oestrogen

Conversion of Graafian follicle to corpus lutetium

Question 7

what happens in the follicular phase

Answer 7

FSH stimulates follicle development
1st mature follicle is called the Graafian follicle - secretes oestrogen
Oestrogen causes endometrial thickening + thinning of cervical mucus

Question 8

what triggers ovulation

Answer 8

rising oestrogen reaches threshold + triggers LH spike at day 12
Increased LH causes Graafian follicle to rupture and release secondary oocyte

Question 9

what happens in the luteal phase

Answer 9

formation of corpus luteum (produces progesterone)
progesterone causes negative feedback- decreased LH/FSH causes degeneration of corpus luteum
Progesterone is no longer being produced- menstruation is triggered

Question 10

name the 3 stages of the uterine cycle

Answer 10

Proliferative
Luteal
Menstrual

Question 11

when does the proliferative phase happen

Answer 11

days 5-14

Question 12

what happens in the proliferative phase

Answer 12

oestrogen induced growth of endometrial glands + stroma

Increased endometrial thickness + vascularity

Question 13

what happens in the luteal phase of the uterine cycle

Answer 13

progesterone induced glandular secretory activity

Question 14

how long does the menstrual phase last

Answer 14

4-6 days

Question 15

how much blood is lost in the menstrual phase

Answer 15

<80ml blood