Regulation of the Normal Ovarian Menstrual cycle Flashcards
length of cycle
1st day of vaginal bleeding to the next start of bleeding
usually 25-30
classification of polymenorrheic
-cycles <21 days (from start to start is more frequent than 21 days)
Oligomenorrheic
cycles prolonged >35 days
Menstrual irregularities are typically at these stages of life
extremes of reproductive life. ie. menarche and menopause.
variability of the cycle is seen in the phase
follicular
finicky
Oogenesis begins in
utero
first half of the cycle this hormone is in charge
estrogen
follicular phase comprises what part of the cycle
- First day of menses until ovulation
____provides the signal for recruitment of a cohort of follicles in the ovary.
FSH
With fraternal twins two follicles become dominant..
Midfollicular Phase (Selection
Lower basal body temperatures and the development of the follicle occur in this phase
follicular
Midfollicular Phase (Selection) is characterized by
Characterized by selection of one dominant follicle from the cohort of growing follicles that were stimulated by FSH.
Here the ovary is the least hormonally active and so serum levels of estradiol and progesterone are lower
Follicular
This phase is characterized by rapid follicular growth
Late Follicular Phase (Dominance)
Luteal phase begins
and ends on
on the day of the LH surge and ends at the onset of the next menses.
Ovulation takes place 36-40hr after
the LH surge.
The secretory activity and functional lifespan of the CL is dependent on
appropriate LH support (14 days). Unless implantation occurs
what happens if implantation occurs
HCG from the developing embryo rescues the CL, involution occurs.
luteal phase defects can become a problem because women don’t get to this point
what happens in the late luteal phase if implantation does not occur
There is a decline in progesterone, estradiol and inhibin. The reduction in estradiol restores the ability of the pituitary to respond to GnRH signals. The GnRH pulse frequency causes a predominance of FSH secretion. The increase in FSH during this phase is key in initiating recruitment of follicles for the ensuing cycle. It appears
Early Luteal Phase
prior to ovulation the granulosa cells enlarge and accumulate a yellow pigment (lutein). During the 3 days following ovulation LH transformed granulosa cells and theca cells luteinize and become a structure known as the corpus luteum CL. This transient endocrine organ secretes progesterone and its function is to prepare the estrogen primed endometrium for implantation of the fertilized ovum.
cervix would feel softer and more open during
follicular phase
the fall of this hormone leads to menstrual cycle
progesterone
fertilization usually occurs at this location in the fallopian tube
ampullary portion
theca cells are associated with
LH
corpus lutetium produces
progesterone
get’s endometrium ready to support fertilized ovum
why is the Luteal phased more predictable
that’s how long the corpus lutetium can survive
what happens if implantation occurs
on the 14th day the embryo will take over with hcG
endometrium in the follicular phase
proliferative phase
cervical mucus in thinner and clearer to facilitate the passage of sperm
the leuteal phase is known as the
secretory phase
progesterone is responsible for making endometrial lining mature and ready for an ovum
thick mucus
cramps are associated with
the presence of prostoglandins
what is the physiology behind the shedding of the endometrium caused by the fall in progesterone
vessels constrict cause loss of blood supply
combination of endometrium blood and dish
