Menstrual Cycle Flashcards
what is primary amenorrhoea
the failure to establish menstruation by 16 years old
what is secondary amenorrhoea
stopping of a previously normal menstruation for over 6 months
what is oligomenorrhoea
infrequent menstruation
what is menorrhagia
excessive menstrual loss
how to fibroids cause menorrhagia
by increasing the surface area
what are common causes for menorrhagia
fibroids, polyps, endometrial cancer, bleeding disorders
what is dysmenorrhoea
pain during menstruation
what is endometriosis
growth of plaques made of endometrium growing outside of the uterus
what can you give to treat endometriosis
GnRH against - this will desensitise the GnRH receptors to switch off the HPG axis and so oestrogen won’t be produced to help the plaques grow
why are GnRH agonists not good for long term treatment
the lack of oestrogen produced can cause osteoporosis
what are the 2 layers which make up the endometrium
- functional layer
2. basal layer
what is the functional layer of the endometrium
the hormone responsive layer which grows and sheds if fertilisation doesn’t occur
what is the basal layer of the endometrium
the cells that grow to give the functional layer
true or false: low levels of oestrogen cause a positive feedback response
false
true or false: high levels of oestrogen cause a positive feedback response
true
is there a positive or negative feedback mechanism in the presence of oestrogen and progesterone
negative
how can progesterone be used in a contraceptive pill
thickens the cervical mucus to prevent sperm from entering
at the start of the cycle, what does a rise in FSH cause
follicular development
what cells does the FSH bind to
granulose cells
what will the follicle begin secreting when it has matured
oestrogen and inhibin
after an initial increase in FSH, what causes the FSH levels to fall
the inhibin produced by the mature follicle
what causes the LH surge
high levels of oestrogen produced from the follicle cause a positive feedback response, causing a large increase in LH
what does the LH surge allow to happen
ovulation
for the follicle to finish meiosis 1 and start meiosis 2
what is left in the ovary after ovulation
corpus luteum
what hormones does the corpus lutuem produce
oestrogen and progesteorne and inhibin
why do the LH and FSH levels decrease after ovulation
the oestrogen and progesterone released by the corpus luteum cause a negative feedback response
inhibin also prevents FSH production
what happens if fertilisation occurs
HCG is produced which has the same effect as LH
where is HCG produced from
syncytiotrophoblast
what do FSH and LH do
cause follicular development and ovulation as well as the release of oestrogen
what happens to the initial levels of LH and FSH in menopause
they increase
