TYPOTHALAMIC PITUITARY GONADAL AXIS Orimary Hormones involved in endocrineregulation ofreproduction in.mn hypothalamus posteriorpituitary oxytocin gonads estradiol progesterone testosterone dihydrotestosterone Tuctiveract prostaglandinF2a Gonadotropin ReleasingHormone GnRH peptide pulsatile how regulatesgonadotropins fatale thffaffffaffman pulsatile helpspreventGnRHreceptordownregulation TGNRHpulsefreqTFS.HU release ErIEh f.ir uafetreleas bindsGnRHRongonadotrophs 81884k amaemae.am GalinkedGPCR bind P3intuxofcazt SETHI ANTERIORPITUITARY HORMONES horlonic Gonadotropins glycoproteinhormonesproducedbyplacenta rpift .net ratherthana regulatedbyhypothalamus equinechorionicgonadotropin bindsFSHR LHCGR long 2life 3 5days hCG humanchorionicgonadotropin FindsLHCAR long12life 24hours AnteriorPituitaryHormones FSH longer1 2 life exogenous estrussynchronizationprotocols administration fertilitytreatment longer1 2 lifethanLH FSH glycoproteins long'klife 3 4hours .FSHRigranulos.az tshortlzlifei20min sertoll.LHCGR granulosa linked cAMP tthecatleydi .GS producedbygonadotropins pulsatile a subunit identicalbetweenallglycoproteins Bsubunit unique iteration.cl differentiationsteroidogenesis bcGslinked GONADAL HORMONES Synthesis FSH4H bindto receptorsactivateGslinkedGPCRs production ofCAMP activateproteinkinaseA steroldogenesis 2cell 2gonadotropinprocess firststeps thecacells leydigcells sertotic last orzsteps.grsacnul testis Ovary cholesterol LCYPHAI 3B SD PS 04 CYP I 17104 CYPHAL 3BHSD PS CYP7 YP17 CYPH YPF cholesterol 04 170H PS P4 stimulated by LHER stimulatedby FSHI DHEA IBHSD P4 CYPHI ya 170H PS CYP7 DHEA MOH Py 3B HSD CYPH BHSAYTHELMB.HN 05 17BHSD estradiol cypy gareductase EZ DHT enzymeexpressedbygranulosa theca ITBHSD enzymeONLY expressed by granulosacells CYP9 enzymeONLY expressed by thecacell YP17 enzymeprimarilyexpressedbythecacells canbeexpressedbygranulosacells 3B HSD BasicstructureofGonadalSteroids protein peptidehormones GnRH glycoproteinhormones SH steroidhormones testosterone leydigcells estradiol Sertolicells progesterone lutealcells androgens Mecacells estrogens granulosa GeneralReceptorType nuclear progesterone estradiol testosterone GPCR LH FSH GnRH ReceptorTypes estrogenCERABB progesterone PR androgen AR testosterone leydigcells testosterone dihydrotestosterone Sertolicells estradiol theca androgen gonadsFinhibin progesterone anteriorpituitaryFISH granulosa estrogen luteal progesterone hormones Parade Ayan synthesis releaseofgonadotropins dihydrotestosterone inhibits inhibits progesterone inhibits testosterone activin stimulatesFSH Inhibin inhibitsFSH LH inhibin FSH sad hormones testosterone estradiol progesterone teletIprogesterone estradiol toniccenter male female 0 surgecenter females hormones GPCR LH GnRH androgenreceptor DHT activin growthfactor proteinhormone inhibin notprotein ANIMAL PHYSIOLOGY I The following diagrams depict the different steroidogenic pathways associated with the gonads. Fill in the empty rectangles with the appropriate steroid hormone or precursor. Fill in the dashed lines with the appropriate steroidogenic enzyme. Ovary CYP IAI PS CYP 7 3B HSD PH MOH PS CYP17 YPM 1 OH P4 DHEA CYP17 3BASD All MBHSD T cypia El MB HSD CYP19 1 ANIMAL PHYSIOLOGY I CYPHAI 3BHSD PS MOH PS PH CYPH 1 CYPM CYPH OH PY YPM DHEA 3BHSD All MBHSD CYP 9 EZ T Sa reductase DHT 2