Endocrine Development Hormone from hormon (Gk) to Table of Contents| ... Hormones Produced by endocrine glands – ductless glands that secrete hormones into the ... secreted by the magnocellular

Download Endocrine Development Hormone from hormon (Gk) to   Table of Contents| ... Hormones Produced by endocrine glands – ductless glands that secrete hormones into the ... secreted by the magnocellular

Post on 26-May-2018

212 views

Category:

Documents

0 download

Embed Size (px)

TRANSCRIPT

<ul><li><p>EndocrineDevelopmentHormone from hormon (Gk) to set in motion, to urge on (E.H. Starling 1866-1927)</p><p>1</p></li><li><p>Objectives</p><p> Understandingofhormonetypes Focusonhypothalamusandpituitarydevelopment Understandingofendocrineglanddevelopment Understandingofendocrinedevelopmentalfunctions Briefunderstandingofmolecularregulationandsignalling</p><p>mechanisms</p><p>2</p></li><li><p>Citation: TheDevelopingHuman:clinicallyorientedembryology9th ed.KeithL.Moore,T.V.N.Persaud,MarkG.Torchia.Philadelphia,PA:Saunders,2011.Chapter9 PharyngealApparatus,Face,andNeckChapter12 UrogenitalSystem</p><p>Citation: Larsen'shumanembryology4thed.Schoenwolf,GaryC;Larsen,WilliamJ,(WilliamJames).Philadelphia,PA :Elsevier/ChurchillLivingstone,c2009.Chapter16 DevelopmentofthePharyngealApparatusandFaceChapter15 DevelopmentoftheUrogenitalSystem</p><p>3</p><p>Nussey,S.andWhitehead,S.(2001).Endocrinology AnIntegratedApproach.UKOxford:BIOSScientificPublishers.ISBN10:1859962521.DetailedTableofContents |BookshelfLinkChapter1.PrinciplesofendocrinologyChapter2.TheendocrinepancreasChapter3.ThethyroidglandChapter4.TheadrenalglandChapter5.TheparathyroidglandsandvitaminDChapter6.ThegonadChapter7.ThepituitaryglandChapter8.Cardiovascularandrenalendocrinology</p></li><li><p>4</p><p>Hormones</p><p>Producedbyendocrineglands ductlessglandsthatsecretehormonesintotheblood</p><p> Aminoacidderivatives noradrenaline(norepinephrin),adrenalin(epinephrin),thyroidhormone</p><p> Peptidesandproteins Thyroidstimulatinghormone,leutenising hormone,folliclestimulatinghormone(HPGaxis)</p><p> Steroids androgens,glucocorticoids(regulateinflammation),mineralocorticoids(saltandwaterbalance)</p><p>Allhormonesactuponcellsindifferenttissuesandcanbeclassifiedbythe"distance"oftheiraction,theclassicaldescriptionisthathormonesaredeliveredbytheblood.</p><p> Autocrine actsonself(extracellularfluid) e.g.cytokinessuchasinterleukin1inmonocytes Paracrine actslocally(extracellularfluidorblood) e.g.fgf,Wnt,shh, Endocrine actsbysecretionintobloodstream(endocrineorgansarerichlyvascularized).</p><p>HormoneReceptors cellsurface modifiedaminoacids,peptides,proteins e.g.FSHreceptor,Gproteincoupled</p><p>receptor intracellularcytoplasmic/nuclear steroids androgenreceptor,Nuclearreceptorsubfamily</p><p>3,C4(NR3C4)</p></li><li><p>5</p><p>Thepinealisaconeshapeddiverticulumoftheroofofthediencephalon</p><p> Pineconeshaped Secretesmelatonin Producedbypinealocytes Inputfromvisualsystem Hasaroleintheinhibitionof</p><p>gonadotrophichormoneswhenitisdamaged,prematurepubertyensues.</p><p> Diminishesafterpuberty Notisolatedbytheblood</p><p>brainbarrier richvasculature</p></li><li><p>6</p><p>Positionoftheadultpinealgland</p></li><li><p>7</p><p>Thehypothalamus controlsanteriorpituitaryandformstheposteriorpituitaryHormones Thyrotrophin releasinghormone(TRH),Corticotrophinreleasinghormone(CRH),Argininevasopressin(AVP),Gonadotrophin releasinghormone(GnRH),Growthhormonereleasinghormone(GHRH),Somatostatin,Prolactinrelasing factor(PRF),Dopamine</p></li><li><p>8</p><p>Thehypothalamus controlsanteriorpituitaryandformstheposteriorpituitaryHormones Thyrotrophin releasinghormone(TRH),Corticotrophinreleasinghormone(CRH),Argininevasopressin(AVP),Gonadotrophin releasinghormone(GnRH),Growthhormonereleasinghormone(GHRH),Somatostatin,Prolactinrelasing factor(PRF),Dopamine</p></li><li><p>9</p><p>Abbreviations:AHA,anteriorhypothalamicarea;AR,arcuate nucleus;DMN,dorsomedial nucleus;MB,mammillarybody;ME,medianeminence;MN,medialnucleus;OC,opticchiasm;PHN,posteriorhypothalamicnucleus;POA,preoptic area;PVN,paraventricularnucleus;SCN,suprachiasmatic nucleus;SO,supraoptic nucleus;VMN,ventromedialnucleus</p><p>Endocrinology:AnIntegratedApproach.Nussey S,WhiteheadS.Oxford:BIOSScientificPublishers;2001</p><p>Thenucleiofthehypothalamus</p></li><li><p>10</p></li><li><p>11</p></li><li><p>12</p><p>Pituitarydevelopmentmovie Interactionbetweenthefloorofthediencephalonandtheectodermalroofofthestomadeum</p></li><li><p>13</p><p>Rathkes pouch thehypophysial diverticulum formstheanteriorlobeevidentat45weeksThedowngrowth oftheneuroectoderm theneurohypophysial diverticulumformstheposteriorlobe</p></li><li><p>14</p><p>Pituitarydevelopmentlate</p><p>Connectionwiththeoralcavityislostasthesphenoidbonedevelopsaspartofthechondocranium atthebaseoftheskull.Thepituitarybecomesencasedinthesella turcica(turkish saddle)</p></li><li><p>15</p><p>Pituitarydevelopmenttimeline</p><p>Week4 hypophysial pouch,Rathkes pouch,diverticulumfromroofWeek5 elongation,contactsinfundibulum,diverticulumofdiencephalonWeek6 connectingstalkbetweenpouchandoralcavitydegeneratesWeek8 basophilicstainingcellsappearWeek9 acidophilicstainingcellsappearWeek10 growthhormoneandACTHdetectableWeek16 adenohypophysis fullydifferentiatedandTSHincreasestopeakat22weeksWeek20to24 growthhormonelevelspeak,thendeclineBirth secondTSHsurgeanddecreasespostnatal</p></li><li><p>16</p><p>Thevascularsystemofthepituitary</p><p>Thepituitaryglandmaintainsconnectionswiththebrainbutsitsoutsideofthebloodbrainbarrier.</p><p>Thepituitaryhasoneoftherichestbloodsuppliesofanywhereinthebody.</p><p>Theposteriorlobeissuppliedbytheinferiorhypophyseal artery</p><p>Theanteriorlobeissuppliedbythesuperiorhypophyseal artery</p></li><li><p>17</p><p>Thevascularsystemofthepituitary</p><p>Thelongportalvesselsofthesuperiorhypophyseal arteryformsthebasisofthehypothalamohypophyseal portalsystem.</p><p>Inhibitoryorstimulatingpeptidesarereleasedfromthemedianeminenceandquicklytransportedtotheanteriorpituitary.</p><p>Oxytocinandvasopressinaresecretedbythemagnocellularneurosecretory cellsthathaveaxonalprojectionsintotheposteriorpituitary</p></li><li><p>18</p><p>Inductionofpituitarydevelopmentinthemouse</p></li><li><p>19</p><p>Differentiationofthesixmatureendocrinecelltypesoftheanteriorpituitaryisdeterminedbytheactionofacascadeoftranscriptionfactors</p></li><li><p>20</p><p>Thyroiddevelopment</p><p>Functionsfromweek10,requiredforneuraldevelopment,stimulatesmetabolism(protein,carbohydrate,lipid),reduced/absence=cretinism</p><p>Hormones (aminoacidderivatives)Thyroxine (T4),Triiodothyronine (T3)</p><p>Beginsat24daysasendodermalthickeningwhichoutpouches toformthethyroidprimordium.Asthetongueandthyroidgrowsthethyroiddescendsintotheneckventraltothehyoidboneandlaryngealcartilages.Theductthatisleftbehind thethyroglossal ducteventuallydisappears</p></li><li><p>21</p><p>Stage13 week45</p></li><li><p>22</p><p>Sagittalviewofthyroiddevelopmentinthecontextofthedevelopingtongue</p></li><li><p>23</p></li><li><p>24</p><p> thyroidmedianendodermalthickeninginthefloorofpharynxbetweenthetuberculum impar andthecopula</p><p> Thisoutpouches toformthethyroiddiverticulum tonguegrows,cellsdescendinneck thyroglossal duct proximalendattheforamencecumoftonguethyroglossal duct thyroiddiverticulum hollowthensolid,rightandleftlobes,centralisthmus</p></li><li><p>25</p><p>Parathyroidfunction</p><p> 4glandsintheneckontheposteriorsurfaceofthethyroidaboutthesizeofagrainofrice</p><p> ParathyroidHormone Increasecalciumions[Ca2+]inthebloodstimulatesosteoclasts,increaseCa GITabsorption(oppositeeffecttocalcitoninproducedbytheparafollicular cellsofthethyroidformedfromtheultimobranchial body)</p><p> AdultCalciumandPhosphate Dailyturnoverinhumanwithdietaryintakeof1000mg/day</p><p> secretedbychiefcells Principalcellscordsofcells</p></li><li><p>26</p><p>Parathyroiddevelopment</p><p>Derivedfromthe3rd formstheinferiorand4th pharyngealpouches formsthesuperiorPositionswapsroundduringdevelopmentElongatesasadiverticulumandthensolidifiesinitsfinallocationEpitheliumofthe3rd and4th pouchproliferatesduring5th weektoformsmallnodules,whichisinvadedbyvascularmesenchymetoformbloodvessels</p></li><li><p>27</p><p>ThymusfunctionThymus bonemarrowlymphocyteprecursorsbecomethymocytes,andsubsequentlymatureintoTlymphocytes(Tcells)Thymushormones thymosins stimulatethedevelopmentanddifferentiationofTlymphocytes.Notlimitedtothethymus.</p><p>ThymusDevelopmentEndoderm thirdpharyngealpouchWeek6 diverticulumelongates,hollowthensolid,ventralcellproliferationThymicprimordia surroundedbyneuralcrestmesenchyme,epithelia/mesenchymeinteraction</p></li><li><p>28</p></li><li><p>29</p><p>Schoenwolf: Larsen's Human Embryology, 4th ed.Copyright 2008</p><p>Pancreasdevelopment</p></li><li><p>30</p><p>Pancreas</p><p> 99%exocrinefunction secretionofpancreaticjuicethatincludestrypsin,chymotrypsin,elastase,carboxypeptidase,pancreaticlipase,nucleasesandamylase</p><p>Isletsoflangerhans Alphacells glucagon(increaseglucose) Betacells insulin(decreaseglucose) Deltacells somatostatin (regulatesalphaandbetacells) Gamma(PP)cells pancreaticpolypeptide(selfregulatespancreatic</p><p>functrion)</p><p>PancreasTimeline Week7to20 pancreatichormonessecretionincreases,small</p><p>amountmaternalinsulin Week10 glucagon(alpha)differentiatefirst,somatostatin (delta),</p><p>insulin(beta)cellsdifferentiate,insulinsecretionbegins Week15 glucagondetectableinfetal plasma</p></li><li><p>31</p><p>Isletcells(yellow)formduringthebranchingmorphogenesisprocessfromendodermcells.Notethatthepancreasdoesntformbranchesthroughfolding(e.g.lung).Itformsastratifiedepitheliumwhichthencreatesmicrolumens thatcoalesce.</p></li><li><p>32</p><p>Adrenalglandsdevelopadjacenttothegonadsintheurogenitalridge</p><p>Cortex mesenchyme,medullaneuralcrest6th weekcortexbeginsasaggregationofmesenchymeMedullafromsympatheticganglionderivedneuralcrestcellsLatermoremesenchymal cellsarisefromthemesotheliumandenclosethecortexCortexsecretesZona glomerulosa aldosterone(bloodpressure)Zona fasciculata glucocorticoidsZona reticularis androgensMedulla(chromaffin cells)secretes(modifiedsympatheticganglion)20%noradrenaline80%adrenaline</p></li><li><p>33</p><p>Suprarenal(adrenaldevelopment)</p><p>Schematicdrawingsillustratingdevelopmentofthesuprarenalglands.A, At6weeks,showingthemesodermalprimordium ofthefetal cortex.B, At7weeks,showingtheadditionofneuralcrestcells.C, At8weeks,showingthefetalcortexandearlypermanentcortexbeginningtoencapsulatethemedulla.D andE, Laterstagesofencapsulationofthemedullabythecortex.F, Glandofaneonateshowingthefetal cortexandtwozonesofthepermanentcortex.G, At1year,thefetal cortexhasalmostdisappeared.H, At4years,showingtheadultpatternofcorticalzones.Notethatthefetal cortexhasdisappearedandthattheglandismuchsmallerthanitwasatbirth(F).Zona reticularis presentat3yearsold</p></li><li><p>34</p><p>Fetal cortexverylarge secretessteroidprecursorsusedbytheplacentaforthesynthesisofoestrogen.Theglandshrinksastheembryoniccortexregresses.</p></li><li><p>35</p><p>Gonadsasendocrineorgans</p></li><li><p>36</p></li><li><p>37</p><p>Placenta</p><p> Humanchorionicgonadotropin(hCG) likeleutenizing hormone,supportscorpusluteum inovary,pregnantstateratherthanmenstrual,maternalurineinsomepregnancytesting</p><p> Humanchorionicsomatommotropin (hCS) orhumanplacentallactogen stimulate(maternal)mammarydevelopment(possible) functionsimilartogrowthhormone</p><p> Humanchorionicthyrotropin (hCT)orTSH Humanchorioniccorticotropin (hCACTH)orcorticotropinreleasinghormone progesteroneandoestrogens supportmaternalendometrium Relaxin</p></li><li><p>38</p><p>Other</p><p>EndocrineHeartAtrialnatriureticpeptide(ANP) IncreaseFiltrationrate/decreaseNa+reabsorptionEndothelins ET1,ET2,ET3,Vasoconstriction/IncreaseNONitricoxide(NO) VasodilatationEndocrineKidneyRenin IncreaseAngiotensinaldosteronesystemProstaglandins decreaseNa+reabsorptionErythropoietin IncreaseErythrocyte(rbc)production1,25(OH)2vitaminD calciumhomeostasisPrekallikreins IncreaseKinin productionGITEndocrineEntericcontrolofdigestivefunctionGastrin Secretedfromstomach(Gcells),roleincontrolofgastricacidsecretionCholecystokinin smallintestinehormone,stimulatessecretionofpancreaticenzymesandbileSecretin smallintestinehormone(epithelialcells),stimulatessecretionofbicarbonaterichfluidsfrompancreasandliverAdiposeTissueLeptin polypeptidehormoneproducedinadiposeandmanyothertissueswithalsomanydifferentrolesAdiponectin regulationofenergyhomeostasisandglucoseandlipidmetabolism,aswellasactingasanantiinflammatoryonthecellularvascularwallResistin (forresistancetoinsulin,RETN)a108aminoacidpolypeptideandtherelatedresistinlikeproteinbeta(Resistinlikemoleculebeta,RELMbeta)stimulateendogenousglucoseproduction</p></li></ul>

Recommended

View more >