Ovulation, luteinization, luteolysis
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Created by:
rjones6045 on September 18, 2011
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26 terms
Terms | Definitions |
|---|---|
 _____ require stim. of vagina/cervix to ovulate. | induced ovulators |
| Rabbits, minks, ferrets, giant fruit bats, cats, 13 lined ground squirrel, and sumatran rhinos are all examples of? | induced ovulators |
| ____ appear to need a substance in semen to ovulate. | camelids |
| ____ have a 50% of ovulation if mated once. | cats |
| _____ _____ 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. | met. |
| 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. | secondary; primary |
| The _____ phase takes place during metestrus and diestrus. | luteal |
| _______ is the change from follicular cells to luteal cells, which in turn produce______. | luteinization; progesterone |
| Luteolysis happens at the end of____. | proestrus |
| Granulosa cells turn into _____ luteal cells and theca interna cells turn into _____ luteal cells. | large; |
| 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? | C. hemorrhagicum |
| What structure on the follicle is the dominant in diestrus? | Mature CL |
| What structure on the follicle regresses at the end of proestrus? | CL (luteolysis) |
| During what stage of estrus does luteolysis occur? | end of proestrus |
| What hormone is responsible for luteolysis? | PGF2a |
| What process is essential for the return to a new follicular phase? | luteolysis |
| What is the major source of PGF2a in domestic animals that is responsible for luteolysis at the end of proestrus? | uterine endometrium |
| 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. | systemic |
| 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? | equines |
| 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) |
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