menstrual cycle Flashcards
what are the phases associated with the menstrual cycle ?
follicular phase
ovulation
luteal phase
why does ovulation occur ?
due to the mid cycle surge
switch from negative feedback to positive fedback
due to an LH surge
what is the basis for ovulation testing ?
urine detection of LH
what is mittelschmerz ?
mid cycle pain associated with follicle enlargement or rupture
usually mild unilateral pain
what is the luteal phase driven by ?
corpus leuteum that releases progesterone
which decreases FSH and LH due to negative feedback
how long after menses does ovulation happens ?
14 days
what are the hormonal changes that occur if fertilization happens ?
the corpus leuteum is maintained , progesterone production continues
high levels of progesterone keeps the FSH and LH levels at bay
the embryo starts making hCG
what hormone triggers the menstrual cycle ?
a drop in progesterone
what are the two phases associated with the uterine cycle ?
proliferative phase : follicular phase of the ovary
secretory phase : luteal phase of the ovary
when does the proliferative phase happens and what hormones are associated ?
happens after menstruation
and it is stimulated by estrogen
when does the secretory phase of the uterine cycle happen ?
occurs after ovulation
and happens at the same time as the luteal phase , maintaining the thickened endometrium made by estrogen
prepares the endometrium for implantation
what are the histological changes associated with the secretory phase ?
vessels grow and coil
form spiral arteries
what histological process drives menstruation ?
apoptosis of the endometrial cells
what is the most common cause of secondary amenorrhea ?
pregnancy
what are the different results of a progestin challenge and what do they indicate ?
bleeding ? classically PCOS
no bleeding ? menopause
what is mullerian dysgenesis and what are the associated finiding ?
cause of primary amenorrhea
failure of mullerian duct development
everything is normal except there is no uterus or vagina
what is the classic scenario associated with mullerian dysgenesis ?
a normal appearing girl presenting at puberty with no menses
normal breast and pubic hair development
FSH and LH are normal
absent uterus or blind vagina
what are the hormone levels associated with mullerian dysgenesis ?
estrogen and progesterone levels are normal normal FSH and LH levels
these patients are genetically females
what is the effect of prolaction on FSH and LH ?
prolactin inhibits GNRh and hence low FSH and LH
what is the cause of amenorrhea in low body weight ?
low GnRH
what is the pathology associated with amenorrhea in menopause ?
loss of estradiol production
but the estrogen isn’t that low - still produced by adipose tissue
loss of inhibin from the ovaries - so initially more FSH
eventually both FSH and LH levels drop
what are the classic symptoms of menopause ?
hot flashes
vaginal atrophy - thin dry and friable
osteoporosis
cardiovascular disease
what are the component of HRT ?
mainly consist of estradiol
progestins are added in women who have an intact uterus - to prevent endometrial hyperplasia
what is the main indication for HRT ?
reduces hot flashes
improves bone density
what are the possible risks associated with HRT ?
increase risk of stroke
increase risk of breast cancer
what is the cause of amenorrhea in PCOS ?
too many androgens are being made
no egg is released
lack of progesterone surge
no shedding of the endometrium
there is a high LH to FSH ratio
how can a lab diagnosis of PCOS be made ?
total testosterone levels
measure the LH to FSH ratio
what is the treatment for PCOS ?
weight loss
oral contraceptives
spironolactone
which anti hyperglycemic drugs are used for insulin resistance ?
metformin / TZD
what are the complications of PCOS ?
risk of diabetes
acanthosis nigricans
endometrial cancer ( unopposed effect of estrogen )
in secondary amenorrhea , what are the different levels of FSH indicative of ?
low FSH - most likely PCOS
high FSH - most likely menopause
normal FSH - mullerian dysgenesis
