Menstrual Cycle

Question 1

what is the purpose of the menstrual cycle

Answer 1

generate oocyte
facilitate fertilisation
optimise endometrium for implantation
protect developing embryo

Question 2

what is the beginning of the menstrual cycle called for the first time

Answer 2

menarche

Question 3

what is it called when you don’t have a menstrual cycle anymore

Answer 3

menopause

Question 4

what is the follicular phase

Answer 4

easy 1 to 14 and on the list day the oocyte is released

menstruation occurs for first couple days then endometrial thickness starts to increase

Question 5

what is the luteal phase

Answer 5

day 14 - 28 where the cops luteum breaks down and the endometrial thickness increases with glands and blood vessels forming

Question 6

what are the days of the menstrual phase
proliferative phase
secretory phase

Answer 6

men - 1 - 5
pro - 5 - 14
sec - 14 - 28

Question 7

describe the hypothalamo-pituitary-ovarian axis

Answer 7

the hypothalamus send GnRH to the anterior pituitary. AP then released FSH and LH to the ovary

the ovary then releases oestrogen which acts on the anterior pituitary and hypothalamus

Question 8

describe the structure and role of GnRH from the hypothalamus

Answer 8

decapeptide
secreted by mid basal hypothalamic neurones
hourly pulses
transported to pituitary via hypophyseal portal blood system

Question 9

what factors can effect secretion of GnRH from the hypothalamus

Answer 9

bereavement 
anxiety 
time zone
day/night duty 
exercise 
weight loss/gain

Question 10

what cells secrete FSH and LH in the anterior pituitary

Answer 10

basophils

Question 11

what is the structural difference between FSH and LH

Answer 11

FSH has A and B with 4 N’s

LH has A and B but with 3 N’s

Question 12

what is the role of FSH after release from the anterior pituitary

Answer 12

stimulates follicular activity

thus promoting estradiol production from granulose cells

Question 13

What is the role of LH after release from the anterior pituitary

Answer 13

triggers release of egg from dominant follicle

promotes development of the corpus luteum and the production of progesterone

Question 14

what is the negative feedback effect of rising oestrogen

Answer 14

inhibits GnRH, LH and FSH

during the start of the cycle

Question 15

what is the positive feedback effect of rising oestrogen

Answer 15

nearing mid cycle 
high oestrogen (E2) leads to surge in LH which triggers ovulation

Question 16

what is the difference in the number of primordial follicles in a 6 month foetus, at birth and puberty

Answer 16

2,000,000
750,000
400,000

Question 17

how many primordial follicles actually develop and produce an egg

Answer 17

450

no new follicles develop

Question 18

describe the terminology of development from primordial follicle to ovulation

Answer 18

primordial follicle 
primary/prenatal follicle 
secondary/antral follicle 
preovulatory follicle 
ovulation

Question 19

what does proliferation of granulose cells lead to

Answer 19

development of antrum (fluid)

Question 20

what allows communication between oocyte and granulose cells eg passage of low mw materials

Answer 20

gap junctions and cytoplasmic processes

Question 21

what is the difference between theca internal and theca externa of follicular development

Answer 21

granular and highly vascularised - interna

fibrous capsule - externa

Question 22

what is secreted by theca interna cells

Answer 22

androgens

Question 23

what are androgens converted to in granulosa cells

Answer 23

androgens convert to estradiol 17- B

Question 24

what is the role of an empty graafian follicle

Answer 24

granulose cells undergo lutenisation producing the corpus luteum - this then produces progesterone and estradiol 17 b

Question 25

what happens to the corpus luteum if there is no fertilisation

Answer 25

corpus luteum degenerates / fibroses to become corpus albicans

Question 26

what are the 4 cycles within the menstrual cycle

Answer 26

gonadotropic hormone levels ovarian cycle ovarian hormone levels uterine cycle

Question 27

what is the endometrium

Answer 27

lining of uterus

Question 28

what happens to the endometrium during the proliferative phase

Answer 28

endometrium thickens | increase in stroll cells, glands and blood vessels

Question 29

what is the thickness of the endometrium during ovulation

Answer 29

2-3 mm

Question 30

what happens to the endometrium during the secretory phase

Answer 30

``` progesterone is the dominant hormone increase in secretion increase in lipids and glycogen increase in supply 4-6 mm thick ```

Question 31

why is the endometrium optimal for implantation during the secretory phase

Answer 31

stable vascular nutrient rich

Question 32

what happens during menstruation

Answer 32

vasodilation (vasospasm of blood vessels due to PGF2a) necrotic outer layers of endometrium separate from uterus separated tissues and blood unities uterine contractions which leads to expulsion of contents

Question 33

what is mucus, where does it come from and what does it do

Answer 33

produced from columnar glands in the cervix stringy and runny midcycle (spinnbarkeit) facilitates sperm access at ovulation

Question 34

what is the role of mucus within the cervix

Answer 34

tenacious and inelastic in luteal phase prevents microbial ingress and protects developing embryo critical to pregnancy as develops mucus plug

Question 35

what is the range for optimal timing of oval in the menstrual cycle

Answer 35

from about 7 to 18 days but most at day 13/14

Question 36

what is within the combined oral contraception

Answer 36

estradiol and synthetic progesterone

Question 37

how does the pill stop ovulation

Answer 37

inhibits GnRH, FSH and LH which prevent ovulation, keep the endometrium thin and mucus tenacious

Question 38

how do you induce super ovulation

Answer 38

daily injections of FSH | originally extracted from urine of meopausal nuns but now use recombination FSH