Hormonal control of menstrual cycle + disorders

Question 1

What effect does oestrogen have on pit

Answer 1

Low oestrogen inhibits LH release

High oestrogen stimulates it (this feedback loop works by increasing no. of oestrogen receptors)

Question 2

What effects does progesterone have on pit

Answer 2

Low prog stimulates LH and FSH

High prog inhibits it (this feedback loop works by increasing sensitivity)

Question 3

What is the most important hormone in follicular stage

Answer 3

FSH ( can rise as O, P and inhibin are low)

Question 4

What are the two types of cell in follicle

Answer 4

Thecal - make androgens from cholesterol

Granulosa - make oestrogens from androgens (aromatisation) - under influence

Question 5

What do inhibin and activin do

Answer 5

Both secreted by granulosa cells
Inhibin increases androgen synthesis and down regulates FSH
Activin increases FSH binding onto follicles

Question 6

What causes LH surge

Answer 6

oestrogen exceeding positive threshold

Question 7

How and why does ovulation occur

Answer 7

after breakdown of follicle by LH, FSH, proteolytic enzymes and PG

Question 8

What are the actions of LH

Answer 8

Luteneises follice - makes it start producing prog
Resumption of meiosis
ovulation

Question 9

Why does corpus luteum degrade

Answer 9

Degrades as prog switches FSH and LH off and there’s no b-hCG to tell it to keep going on

Question 10

How does menstrual cycle start again

Answer 10

Reduction of P + O and inhibin, brake taken off pituitary and FSH starts again

Question 11

What change occurs in proliferative endometrial phase

Answer 11

Single layer –> pseudostratified

Question 12

What happens in secretory endo. phase

Answer 12

Proliferation stops, start secreting stuff into glands and uterine lumen
Formation of decidua (temporary layer)

Question 13

What are the three layers of endometrium

Answer 13

Basalis (REMAINS)
spongiosum (stroma + exhausted glands)
compactum (decidua)

Question 14

Definition of precocious puberty

Answer 14

Before 8 in a girl

before 9 in a boy

Question 15

Definition of delayed puberty

Answer 15

No secondary sexual characteristics by age of 14

Question 16

Causes of delayed puberty

Answer 16

Central defect:
Anorexia
chronic illness
Kallmann’s

Failure of gonadal function:
turner’s (XX) ovarian dysgenesis
premature ovarian failure

Question 17

Non structural causes of DSD

Answer 17

Turner's (45X)
46 XY (gonadal dysgenesis due to SRY mutation)
androgen insensitivity
5 alpha reductase def
CAH

Question 18

Features of turner’s

Answer 18

wide carrying angle,
webbed neck
short
coarctation of aorta
thyroid problems
deafness
IBD

Question 19

Why does turner’s lead to DSD

Answer 19

STREAK GONADS

Question 20

What happen in 46 XY SRY def

Answer 20

absent anti-mullerian hormone so no prevention of development of uterus vagina, fallopian tube.
No testosterone so foetus virilise

Question 21

What happens in 46 XY DSD with androgen insensitivity

Answer 21

Uterus doesn’t form cause you have AMH
You develop testes due to testosterone
BUT you develop female external genitalia
Will see: female external genitalia, testes descending somewhere, no uterus

Question 22

What happens in 5-a reductase def

Answer 22

Normal male sexual genitalia but doesn’t virilise properly as you can’t make DHT (ambiguous genitalia)

Question 23

What happens in 46 XX DSD

Answer 23

Caused by CAH
Virilisation of female
Fused labia, enlarged clitoris

Question 24

What is primary amenorrhea

Answer 24

Girl that fails to menstruate by age of 16

Question 25

Secondary amenorrhea

Answer 25

absent menstruation >6 months

Question 26

oligomenorrhea

Answer 26

irregular periods for more than 35 days and 4-9 periods a year

Question 27

Causes of hypogonadotrophic hypogonadism

Answer 27

anorexia
head injuries
Kallmann's
systemic disorder (TB)
drugs (prog, dopamine antagonists

Question 28

Causes of pit. problems

Answer 28

adenomas (prolactinoma)
sheehan’s
damage (radio, surgery)
failure of development

Question 29

ovarian problems causing amenorrhea

Answer 29

PCOS - hypertrophic hypogonadism

Question 30

Endometrial disorders causing amenorrhea

Answer 30

primary can be caussed by mullerian defects (absent uterus causing haematocolpos)
secondary can be caused by scarring

Question 31

Ix for amenorrhea

Answer 31

Pregnancy test
Raised LH + test - PCOS
Riased FSH - POF

Question 32

Mx of POF

Answer 32

COCP or HRT

Question 33

What is the diagnositc criteria for PCOS

Answer 33

Rotterdam criteria 2/3
clinical/biochemical hyperandrogenism
Oligo/amenorrhea (>2 years)
US evidence of cystic ovaries
-12 or more follicular cysts+ increased ovarian stroma

Question 34

Mx of PCOS

Answer 34

COCP / cyclical oral progesterone (w/ withdrawal bleed 3-4 months)
This increass sex hormone binding globulin to relieve androgenic symtpoms
If not planning pregnancy:
Lifestyle, cream for hirsutism
Can give co-cyprindol - used in PCOS w/ hirsuitism and acne
GnRH analgoues - only if other treatments don’t work

If planning (help w/ subfertility)
encourage weight loss
clomiphene (SERM) if normal BMI
clomiphene increases fertility for 6 months, increases chance of multiple pregnancy, give w/ / w/o metformin
Laparoscopic ovarian drilling

Question 35

Mx of premenstrual symtpoms

Answer 35

conservative - reduce stress, caffeine, pain relief
moderate - COCP, refer for CBT
Severe- SSRI (but must monitor for 3 months)