Slide set 4 notes

Slide Set 4 Chapters 7, 8 and 9 Estrus Dominant hormone ? Estradiol Dominant structure ? Follicle Metestrus Dominant hormone ? Progesterone (drop in estrogen) Dominant structure ? CL (growing) Ovulation occurs very early Diestrus ? (longest) Animals that don?t have anestrous have long diestrus Dominant hormone ? Progesterone Dominant structure ? Corpus Luteum Proestrus ? proceeds estrus Dominant hormone ? Estradiol Dominant structure - Follicle Most clear anestrus is during pregnancy Progesterone -> negative feedback to hypothalamus Not all animals have as part of estrous cycle Seasonal breeders have anestrous not as part of cycle but if not bred i.e. if short-day breeder -> anestrus during long-day Some queens are seasonal polyestrus (long day) GnRH following trend of LH, FSH, E2 Follicle produces estrogen (is growing making more E2) *Short-day breeders Pineal gland (at top of brain) stops production of melatonin when excessive amounts of light are stimulating nerve In long-day breeders lots of stimulation from light stimulates pineal gland to produce melatonin Recruit a pool of selected follicles, not just one Only one follicle will become antral follicle All others will die (Atresia) *LH does not directly cause ovulation, it starts cascade of events leading to it Left side all about increasing pressure inside follicle/right side about weakening walls Ovulation is just breaking membrane of follicle E2 is converted to P4 Theca interna layer cells experience edema (fluid build up) Collagenase ? enzyme that breaks down collagen (in follicular membrane) Enzymes eat wall from inside out PGE2 ? increase fluid PGF2? ? contracts muscles (increase pressure) Hystimine increases leakiness of capillaries (permeability) All hormones are localized at ova *not in book Antral Follicle Mg ? granulosal cells Ti ? Theca interna cells Produces collaganase ? specifically breaks tunica albuginea Where weak spot develops first is where rupture occurs