3B Learning Objectives Estrous Cycle

ESTROUSCYCLE Definitions estrus periodofsexualreceptivityinfemales estrouscycleseriesofpredictablereproevents ovulation ovulation dayofovulation endofestrus Large D anestrus interruptionofestrus pregnancyseasoninadequatenutrition pathologicalconditions StagesofEstrouscycle longeststage lutealphase longest ovulation initial CLregression CL TTTi large ants progesterone D4 predominanthormone PY me mtdiestms initialCLregression ovulation dominantfolliclehaspotnialtoovulate synthesizes largeamtestradiol EZ Diestrus sexualinacity PhasesofEstrouscycle predominanthormone estm .CL4P4 El pro Proestrus initial CLregression onsetofestrus ressidevelopingdominanto reging LYTE Estrus Visiblebehaviors sexualreceptivity standingheat ovulatorydominantfollick Et Me ovulation developmentofCL developingCL TP4 if significantly daystsynthesizes flutolysis qq.bg secreteinnibindalat 0 Egression Enfeedback late Mutation mmm EstrouscydeandHPGAxis Diestrus highcirculatingP4concentration feedbackon hypothalamus tant pit inhibit GnRH FSH LH D4createsfavorableenvironmentforconcep stimulatesendometrialglandsecretions inhibits myometrialcontractions targetsmammaryglandsstimulates alveolardevelopment luteolysis a regression endofdlestrus JPY stimulated by prostaglandinF2a PGF2a producedsecretedbyuterineendomett Cow dayle beginstoexpress 3cL PGF2a Sow days1214 orestrus Ezbeginningto t treats me sulateinhibi productionbygranulosa favorableenvironmentforfertilization Stimulatebloodflowmucussecretionmyometrial contraction 0feedback E2 onhypothalamus tant pit prostaglandins lipidbasedhormones derivedfrom arachidonic released from phospholipids endometrium phospholipaseA2 stimulatessmoothmusclecontraction not in dog cat low huma TGnRHFSH LH Estrus highconc EZ Stimulationofinhibin bygranulosacells regulationofuterus feedback ontoniccenterofhypoa ant pit EZmediated feedbackpredominates lateproestrus TE2 ttt Stimulateinhibin productionbygranulosacett ofeedback onhypothalamus tant pit inhibit GnRHFSH LH InhibitFSH noreductioninLH ovary uterus E2highthreshold stimulate anRttreleasefromsurgecenter TANRATLHTESH FSHlowerbkinhibin Meestrus TP4 feedbackonhypotant pit inhibition GnRHFSHLH stimulateendometrialglandsecretions inhibit myometrialcontractions stimulatealveolardevelopment Negative PositiveFeedbackMechanisms EZ Ofeedbackontonicanter feedbackonsurgecenter estrus P4 feedbackontoniccenter LHsurge ovulation endofestrus endofE2 feedback surgecenter ps dE2,4P4 wheninhibinincreases follicularphase inhibinissecreted correlatedto EZlevels feedbackonsurgecenter E24P4 feedback on ant pit feedback isgreatest diestrus feedback estrus dhorepinephrinedmelatonin PSP EPP O O O O ifeng.ttIttsfting allspeaeswantto haveoffspringin spring tn tohaveki day tn luteal.gg ghfinitialaregression follicular Dlestrus sexualinactivity matureCL highP4 Proestrusiregressingchdominantfollicle LP44E2 Estrus preovulatoryfollicle high Metestrus ovulation Etherege Diestrus luteal Proestrus follicular Estrus Metestrus luteal earlydevelopingCL TPI highE2dominantfollicle highP4CL Inhibinsecretion ovulation Egression Mdayténgthdmelatonin Inducedovulators vaginal cervicalstimulation surgecenter cats llamas estruspostestruspregnancy Monoestrus dog anestrus.proestrus.esrus.dustrus longdaybreedert spring tmelatonintanRH.FSH.LA mare shortdaybreeders fall TmelatonintanRHFSHLH day of proeslmsvaginaldischarge sheep daylofdlestrus nolongerreceptive PGF2 .no daylofestrus receptive ndats anestru ahvefeedback R4mediatedneg prolongeddinanRH humans ANIMAL PHYSIOLOGY I The graph below represents circulating concentrations of hormones throughout the estrous cycle of a cow. *Indicate which hormone is represented by each colored line. *Indicate which box(es) above the graph represent(s) the different phases and stages of the estrous cycle. *Draw an arrow on the graph to indicate where ovulation occurs. *Draw an arrow on the graph to indicate where luteolysis begins. *Draw an arrow on the graph to indicate where one estrous cycle ends and the next begins. luteolysis CLregression Ha I destroys PY follicular proestms ovulation whereoneestrouscycleendst anotherbegins I luteal follicular ETE metestrus FSH 1 ANIMAL PHYSIOLOGY I The following diagrams depict the hypothalamic-pituitary-ovarian axis during the estrous cycle. Dashed lines are associated with the arrows and (+)/(-) signs. Hormonal stimulation is indicated by a (+) sign and inhibition is indicated by a (-) sign. *Fill in the dashed lines with the appropriate hormone. *Indicate the center that releases each hypothalamic hormone. *Indicate the structure that releases each ovarian hormone. *Indicate the layer that releases each uterine hormone. ESTRUS one GnRH GnRH FSH LH EZ inhibin Ez follicle follicle surge Ez follicle follicle 2 ANIMAL PHYSIOLOGY I EARLY PROESTRUS tonic GnRH FSH LH EZ follicle LATE PROESTRUS tonic GnRH FSH LH Inhibin Ez follicle follicle EZ follicle 3 ANIMAL PHYSIOLOGY I EARLY to MID-DIESTRUS tonic GnRH FSH LH PY P4 py CL CL LATE DIESTRUS GnRH FSH LH P4 P4 PAFA Pt 4