Normal Menstrual Cycle Flashcards Preview

Year 3: Reproduction > Normal Menstrual Cycle > Flashcards

Flashcards in Normal Menstrual Cycle Deck (15)
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1
Q

length of average menstrual cycle

A

28 days

2
Q

What day of the cycle does ovulation usually occur

A

day 14

3
Q

where is GnRh released from and what does it act on

A

Hypothalamus

Acts on pituitary

4
Q

GnRh causes the release of what hormones from the pituitary

A

LH

FSH

5
Q

What effect does FSH have on the ovary

A

Stimulates development of the follicle

Secretion of oestrogen + inhibin

6
Q

What effect does LH have on the ovary

A

Production of oestrogen

Conversion of Graafian follicle to corpus luteum

7
Q

What happens in the follicular phase

A

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

8
Q

What triggers ovulation

A

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

9
Q

What happens in the luteal phase

A

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

10
Q

Name the 3 stages of the uterine cycle

A

Proliferative
Luteal
Menstrual

11
Q

When does the proliferative phase happen

A

days 5-14

12
Q

what happens in the proliferative phase

A

Oestrogen induced growth of endometrial glands + stroma

Increased endometrial thickness + vascularity

13
Q

What happens in the luteal phase of the uterine cycle

A

Progesterone induced glandular secretory activity

14
Q

How long does the menstrual phase last

A

4-6 days

15
Q

How much blood is lost

A

<80ml blood