_____ require stim. of vagina/cervix to ovulate.
Rabbits, minks, ferrets, giant fruit bats, cats, 13 lined ground squirrel, and sumatran rhinos are all examples of?
____ appear to need a substance in semen to ovulate.
____ have a 50% of ovulation if mated once.
_____ _____ in the vagina in induced ovulators cause a GnRH release from the surge center; however, ovulation is still determined by _____ release.
sensory neurons; LH
Cows ovulate in ____ estrus.
Most spp LH surge only lasts ____ to ____. Which spp. is 3-4 days?
12-24 hrs; horse
In most animals, the ____ oocyte is ovulated except for the canine, which ovulates the _____ oocyte, which is why they cant get pregnant for 2-3 days after ovulation.
The _____ phase takes place during metestrus and diestrus.
_______ is the change from follicular cells to luteal cells, which in turn produce______.
Luteolysis happens at the end of____.
Granulosa cells turn into _____ luteal cells and theca interna cells turn into _____ luteal cells.
The neg. feed back of progesterone on the hypothalamus/ant.pit. causes a ______ in GnRH, _____ behavioral estrus, and _____ the pre-ovulatory LH surge.
decrease; prevents; stops
The positive feed back of progesterone on the uterus causes it to secrete _____ and _____ myometrail tone. For what purpose?
uterine milk; reduces; planning for pregnancy
What structure on the follicle is the dominant in late metestrus?
What structure on the follicle is the dominant in diestrus?
What structure on the follicle regresses at the end of proestrus?
During what stage of estrus does luteolysis occur?
end of proestrus
What hormone is responsible for luteolysis?
What process is essential for the return to a new follicular phase?
What is the major source of PGF2a in domestic animals that is responsible for luteolysis at the end of proestrus?
Cows have a _____ _____ mechanism that allows PG2Fa to circulate from the uterine vein and uterine/ovarian arteries allowing very small quantities of PG2Fa to recirculate and cause ______.
countercurrent exchange; luteolysis
The mare and sow have _____ luteolysis mechanisms.
Why do sows take longer to respond to PG2Fa for luteolysis?
b/c they have systemic PG2Fa circulation (and c/c exchange too) which prevents PG2Fa levels from reaching threshold levels (40% first pass metabolism in the lungs)
Which spp. has only a systemic mechanism for luteolysis and is very sensitive to the amts of exogenous PG2Fa?
The hormonal induction of luteolysis begins after 10-12 days of increasing progesterone causing _______ receptors to appear in the ______ of the uterus; second, the CL contains large amounts of ______ which binds to the receptors and triggers a _______ release on a positive feedback system resulting in luteolysis.
oxytocin; endometrium; oxytocin; PG2fa (from the endometrium)