Endocrinology of the menstrual cycle

Question 1

When throughout life does GnRH activity increase

Answer 1

Puberty in females

Question 2

what does FSH do

Answer 2

follicle stimulating hormone - stimulates growth of egg before ovulation

Question 3

what does LH do

Answer 3

lutinising hormone trigger release of the egg

Question 4

what does the ovarian follicle secrete

Answer 4

oestrogen( increase LH)

Question 5

what is the endometrium

Answer 5

inner lining the uterus - each month it thickens then if no pregnancy it sheds in a process called menstruation. if contraception occurs the embryo implants in the endometrium

Question 6

what do the ovaries do

Answer 6

glands that produce egg and hormones - contain follicles and attached to the uterus by the Fallopian tubes - made of ovarian follicles like eggs in a sac

Question 7

what is contained inside an ovarian follicle

Answer 7

oocyte and cells that release oestrogen and progesterone

Question 8

during the development of the ovarian follicle what type of follicle contains the primary oocyte

Answer 8

primordial follicle

13-50 years

Question 9

what part of meiosis is the primary follicle rested in

Answer 9

prophase 1

Question 10

what does the graphian follicle contain

Answer 10

secondary oocyte

Question 11

how does the second devision need to be completed

Answer 11

ovum needs to be fertilised

Question 12

how long does the follicular phase last

Answer 12

1-7/8days

Question 13

in the follicular phase what hormone determines what regulation should be applied by negative feedback

Answer 13

oestrogen

Question 14

what hormone inhibits cells that make FSH

Answer 14

inhibin

Question 15

in the late follicular phase when 1 follicle is secreted wha hormone is produced in high levels

Answer 15

oestrogen

Question 16

when the amount of oestrogen changes in a system what does oestrogen do

Answer 16

changes to psotivie feedback and increased production of other hormones so have surge in LH and FSH

Question 17

why is the FSH surge not as high as the LH surge in the late follicular phase

Answer 17

because inhibin is produced from the mature follicle/graphian to negatively inhibits FSH producing cells

Question 18

What hormone starts meiosis in oocyte and acitvates the endomeitrium and dissolves the follicle and promotes vascular leakage causing it to swell and rupture causing ovulation to occur so oestrogen levels plummet

Answer 18

LH

Question 19

When a mature follicle ruptures what does it release

Answer 19

secondary oocyte and a polar body

Question 20

how does a corpus luteum form

what does it secrete

Answer 20

remnants of the ruptured follicle - lutinization
appears yellow
progesterone - dominant

Question 21

what does progesterone do

Answer 21

inhibits FSH and LH so stops further follicle development and ovulation in the current cycle
prepares uterus for pregnancy

Question 22

in the luteal phase what hormones are stimulating

Answer 22

progesterone - keep LH and FSh down

oestrogen - moderate positive feedback but not as dominant

Question 23

if fertilisation does not occur what happens

what happens to CL
and hormones

Answer 23

CL degenerates 
progesterone falls
uterus loses endocrine support 
menstruation 
FSH and LH get to work again

Question 24

if fertilisation does occur what happens

what hormone maintains the CL

Answer 24

CL maintained by hCG ( human chorionic gonadotrophin) - maternal recognition of pregnancy produced by trophoblast cells surrounding a growing embryo which eventually forms placenta and become cl of pregnancy
maintains uterine lining until placenta takes over at 3 months

Question 25

what is the chorion

Answer 25

double layered membrane formed by trophoblast cells and the extra-embryonic mesoderm

Question 26

what is the function of combined hormonal contraceptives CHC

Answer 26

inhibit ovulation - oestrogen and progesterone no surge of others so no ovulation have contraceptive effect on cervical mucus and endometrium too oestrogen causes endometrium to proliferate and grow progesterone prevents hyperplasia ( excessive growth) of Endometrium

Question 27

Which one of the phases represents the changes in ovaries during menstrual cycle?

Answer 27

Follciluar phase Menstrual and secretory are changes in the uterus High concentration of oestrogen is responsible for the LH surge which causes ovulation during the middle of menstrual cycle.

Question 28

Which hormone specifically inhibits Follicle-Stimulating Hormone (FSH)

Answer 28

inhibin

Question 29

How does low concentration of oestrogen regulates hormone production by hypothalamus and pituitary in early follicular phase?

Answer 29

Through negative feedback | Positive feedback later on

Question 30

High concentration of oestrogen is responsible for the LH surge which causes ovulation during the middle of menstrual cycle. true or false

Answer 30

True- grpahian follicle for prodcution of follicle brining back postive feedback - repsobilbe for ovulation (lH)

Question 31

Which hormone has a dominating effect on controlling GnRH, FSH and LH production in the Luteal phase?

Answer 31

Progesterone | Both esotrgne and progesterone are produced in the luteal phase

Question 32

what are the two layers of the uterus

Answer 32

endometrium - internal layer | myometrium - external smooth muscle layer

Question 33

what does oestrogen prepare

Answer 33

Oestrogen prepares the way: promotes growth of endometrium & myometrium promotes formation of progesterone receptors

Question 34

in the luteal phase progesterone acts on oestrogen - primed endometrium to do what

Answer 34

Loosens and softens connective tissue - makes implantation easier Promotes secretion of nutrients (glycogen) Quietens uterine activity

Question 35

what happens if fertilisation dosent occur be specific | what happens to vessels to cause tissue death

Answer 35

No occupants..no hCG so Corpus Lutem degenerates Progesterone (and oestrogen) support lost Uterine prostaglandins → vasoconstriction → tissue death Blood and endometrial debris (menses) lost through vagina

Question 36

Dysmenorrhea

Answer 36

painful periods

Question 37

Menorrhagia

Answer 37

heavy or prolonged periods

Question 38

Amenorrhea

Answer 38

Absence of periods (primary or secondary)

Question 39

Oligomenorrhea

Answer 39

light periods

Question 40

explain the mechanism of action of the combined pill

Answer 40

low dose of oestrogen descrease FSH production, decreased development of the follicle and no ovulation. progesterone makes the cervical mucus sperm unfriendly decreased LH from the anterior pituitary decreased GnRH from hypothalamus decreased motility of Fallopian tube

Question 41

what is the progesterone only pill

Answer 41

Low dose progestogen taken continuously (e.g. either norethisterone or levonorgestrel). Makes cervical mucus inhospitable to sperm. Hinders implantation through its effect on the endometrium and on the motility and secretions of the fallopian tubes. Menstruation often ceases initially but usually returns with prolonged use. Main adverse effects Breakthrough bleeding and irregular menses.