Physiology - Menstrual Cycle Flashcards
what does GnRH stimulate?
release of FSH and LH from the anterior pituitary
what effect do FSH and LH have on follicles?
FSH initiates follicular growth
LH stimulates further development
what effect do FSH and LH have on the ovaries?
stimulate the follicles to secrete oestrogen
what secretes progesterone?
the corpus luteum
what effect to progesterone and oestrogen have on the endometrium?
prepare and maintain it for implantation
how long is a normal menstrual cycle?
24-38 days
no more than 9 days variation
how long should bleeding last in a normal menstrual cycle?
no more than eight days
when does the menstrual phase occur?
roughly the first five days of the cycle
what happens in the ovaries during the menstrual phase?
primary follicles develop into secondary follicles under the influence of FSH
what happens in the uterus during the menstrual phase?
fall in oestrogen + progesterone causes release of prostaglandins, causing arteriolar construction
cells die off and stratum functionalis sheds
what time period has the main impact on the length of a menstrual cycle?
the time between menstruation and ovulation
what happens in the ovaries during the preovulatory phase?
secrete oestrogen
one follicle outgrows the rest and becomes the Graafian follicle
what happens in the uterus during the preovulatory phase?
new stratum functionalis produced
endometrial thickness doubles
when does ovulation occur in a 28 day cycle?
day 14
what happens in the ovaries during the ovulatory phase?
oestrogen stimulates GnRH, which causes an LH surge
this causes expulsion of the oocyte from the Graafian follicle
how long does the postovulatory phase last?
14 days - constant
what happens in the ovary during the postovulatory phase?
follicle becomes the corpus luteum under the influence of LH
what hormones does the corpus luteum secrete?
progesterone
oestrogen
relaxin
inhibit
what do the endometrial glands secrete during the postovulatory phase?
glycogen
what are pre-menstrual disorders (PMD)?
when premenstrual symptoms have an impact on daily living
for a diagnosis of PMD, when must symptoms occur?
must be cyclical
occur in the post-ovulatory or luteal phase
what are some physical symptoms of PMD?
breast tenderness bloating headache skin problems weight gain
what are some psychological symptoms of PMD?
mood swings
anger
depression
suicidal ideation
what are some behavioural symptoms of PMD?
sleep disturbance appetite changes restlessness poor concentration confusion
