Placenta - Wikipedia

The placenta is a temporary fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating ... Placenta FromWikipedia,thefreeencyclopedia Jumptonavigation Jumptosearch Organthatconnectsthefoetustotheuterinewall Thisarticleisaboutthehumanplacenta.Forgeneralinformationabouttheplacentaasanorganinbiology,seeplacentation.FortheancientRomanBread,seeplacenta(food).Fortheexpulsionoftheplacenta,orafterbirth,seeplacentalexpulsion. PlacentaPlacentaHumanplacentafromjustafterbirthwiththeumbilicalcordinplaceDetailsPrecursordeciduabasalis,chorionfrondosumIdentifiersLatinPlacentoMeSHD010920TEE5.11.3.1.1.0.5Anatomicalterminology[editonWikidata] Theplacentaisatemporaryfetalorganthatbeginsdevelopingfromtheblastocystshortlyafterimplantation.Itplayscriticalrolesinfacilitatingnutrient,gasandwasteexchangebetweenthephysicallyseparatematernalandfetalcirculations,andisanimportantendocrineorganproducinghormonesthatregulatebothmaternalandfetalphysiologyduringpregnancy.Theplacentaconnectstothebabyviatheumbilicalcord,andontheoppositeaspecttothematernaluterusinaspeciesdependentmanner.Inhumans,athinlayerofmaternaldecidual(endometrial)tissuecomesawaywiththeplacentawhenitisexpelledfromtheuterusfollowingbirth(sometimesincorrectlyreferredtoasthe'maternalpart'oftheplacenta).Placentasareadefiningcharacteristicofplacentalmammals,butarealsofoundinmarsupialsandsomenon-mammalswithvaryinglevelsofdevelopment.[1] Mammalplacentasprobablyfirstevolvedabout150millionto200millionyearsago.Theproteinsyncytin,foundintheouterbarrieroftheplacenta(thesyncytiotrophoblast)betweenmotherandbaby,hasacertainRNAsignatureinitsgenomethathasledtothehypothesisthatitoriginatedfromanancientretrovirus:essentiallya"good"virusthathelpedpavethetransitionfromegg-layingtolive-birth.[2][3][4] ThewordplacentacomesfromtheLatinwordforatypeofcake,fromGreekπλακόεντα/πλακοῦνταplakóenta/plakoúnta,accusativeofπλακόεις/πλακούςplakóeis/plakoús,"flat,slab-like",[5][6]withreferencetoitsround,flatappearanceinhumans.Theclassicalpluralisplacentae,buttheformplacentasismorecommoninmodernEnglish. Contents 1Phylogeneticdiversity 2Structure 2.1Geneandproteinexpression 3Physiology 3.1Development 3.2Placentalcirculation 3.2.1Maternalplacentalcirculation 3.2.2Fetoplacentalcirculation 3.3Birth 3.4Microbiome 4Functions 4.1Nutritionandgasexchange 4.2Excretion 4.3Immunity 4.4Endocrinefunction 4.5Immunologicalbarrier 4.6Other 5Clinicalsignificance 6Societyandculture 7Additionalimages 8Seealso 9References 10Externallinks Phylogeneticdiversity[edit] Althoughallmammalianplacentaehavethesamefunctions,thereareimportantdifferencesinstructureandfunctionindifferentgroupsofmammals.Forexample,human,bovine,equineandcanineplacentaeareverydifferentatboththegrossandthemicroscopiclevels.Placentaeofthesespeciesalsodifferintheirabilitytoprovidematernalimmunoglobulinstothefetus.[7] Structure[edit] Placentalmammals,suchashumans,haveachorioallantoicplacentathatformsfromthechorionandallantois.Inhumans,theplacentaaverages22 cm(9 inch)inlengthand2–2.5 cm(0.8–1 inch)inthickness,withthecenterbeingthethickest,andtheedgesbeingthethinnest.Ittypicallyweighsapproximately500 grams(justover1 lb).Ithasadarkreddish-blueorcrimsoncolor.Itconnectstothefetusbyanumbilicalcordofapproximately55–60 cm(22–24 inch)inlength,whichcontainstwoumbilicalarteriesandoneumbilicalvein.[8]Theumbilicalcordinsertsintothechorionicplate(hasaneccentricattachment).Vesselsbranchoutoverthesurfaceoftheplacentaandfurtherdividetoformanetworkcoveredbyathinlayerofcells.Thisresultsintheformationofvilloustreestructures.Onthematernalside,thesevilloustreestructuresaregroupedintolobulescalledcotyledons.Inhumans,theplacentausuallyhasadiscshape,butsizevariesvastlybetweendifferentmammalianspecies.[9] Theplacentaoccasionallytakesaforminwhichitcomprisesseveraldistinctpartsconnectedbybloodvessels.[10]Theparts,calledlobes,maynumbertwo,three,four,ormore.Suchplacentasaredescribedasbilobed/bilobular/bipartite,trilobed/trilobular/tripartite,andsoon.Ifthereisaclearlydiscerniblemainlobeandauxiliarylobe,thelatteriscalledasuccenturiateplacenta.Sometimesthebloodvesselsconnectingthelobesgetinthewayoffetalpresentationduringlabor,whichiscalledvasaprevia. Geneandproteinexpression[edit] Furtherinformation:Bioinformatics§ Geneandproteinexpression About20,000proteincodinggenesareexpressedinhumancellsand70%ofthesegenesareexpressedinthenormalmatureplacenta.[11][12]Some350ofthesegenesaremorespecificallyexpressedintheplacentaandfewerthan100genesarehighlyplacentaspecific.Thecorrespondingspecificproteinsaremainlyexpressedintrophoblastsandhavefunctionsrelatedtofemalepregnancy.ExamplesofproteinswithelevatedexpressioninplacentacomparedtootherorgansandtissuesarePEG10andthecancertestisantigenPAGE4andexpressedincytotrophoblasts,CSH1andKISS1expressedinsyncytiotrophoblasts,andPAPPA2andPRG2expressedinextravilloustrophoblasts. Physiology[edit] Development[edit] Placenta Theinitialstagesofhumanembryogenesis. Furtherinformation:Placentation Theplacentabeginstodevelopuponimplantationoftheblastocystintothematernalendometrium.Theouterlayeroftheblastocystbecomesthetrophoblast,whichformstheouterlayeroftheplacenta.Thisouterlayerisdividedintotwofurtherlayers:theunderlyingcytotrophoblastlayerandtheoverlyingsyncytiotrophoblastlayer.Thesyncytiotrophoblastisamultinucleatedcontinuouscelllayerthatcoversthesurfaceoftheplacenta.Itformsasaresultofdifferentiationandfusionoftheunderlyingcytotrophoblastcells,aprocessthatcontinuesthroughoutplacentaldevelopment.Thesyncytiotrophoblast(otherwiseknownassyncytium),therebycontributestothebarrierfunctionoftheplacenta. Theplacentagrowsthroughoutpregnancy.Developmentofthematernalbloodsupplytotheplacentaiscompletebytheendofthefirsttrimesterofpregnancyweek14(DM). Placentalcirculation[edit] Maternalbloodfillstheintervillousspace,nutrients,water,andgasesareactivelyandpassivelyexchanged,thendeoxygenatedbloodisdisplacedbythenextmaternalpulse. Maternalplacentalcirculation[edit] Inpreparationforimplantationoftheblastocyst,theendometriumundergoesdecidualization.Spiralarteriesinthedeciduaareremodeledsothattheybecomelessconvolutedandtheirdiameterisincreased.Theincreaseddiameterandstraighterflowpathbothacttoincreasematernalbloodflowtotheplacenta.Thereisrelativelyhighpressureasthematernalbloodfillsintervillousspacethroughthesespiralarterieswhichbathethefetalvilliinblood,allowinganexchangeofgasestotakeplace.Inhumansandotherhemochorialplacentals,thematernalbloodcomesintodirectcontactwiththefetalchorion,thoughnofluidisexchanged.Asthepressuredecreasesbetweenpulses,thedeoxygenatedbloodflowsbackthroughtheendometrialveins. Maternalbloodflowisapproximately600–700 ml/minatterm. Thisbeginsatday5-day12[13] Fetoplacentalcirculation[edit] Furtherinformation:Fetalcirculation Deoxygenatedfetalbloodpassesthroughumbilicalarteriestotheplacenta.Atthejunctionofumbilicalcordandplacenta,theumbilicalarteriesbranchradiallytoformchorionicarteries.Chorionicarteries,inturn,branchintocotyledonarteries.Inthevilli,thesevesselseventuallybranchtoformanextensivearterio-capillary-venoussystem,bringingthefetalbloodextremelyclosetothematernalblood;butnointerminglingoffetalandmaternalbloodoccurs("placentalbarrier").[14] Endothelinandprostanoidscausevasoconstrictioninplacentalarteries,whilenitricoxidecausesvasodilation.[15]Ontheotherhand,thereisnoneuralvascularregulation,andcatecholamineshaveonlylittleeffect.[15] Thefetoplacentalcirculationisvulnerabletopersistenthypoxiaorintermittenthypoxiaandreoxygenation,whichcanleadtogenerationofexcessivefreeradicals.Thismaycontributetopre-eclampsiaandotherpregnancycomplications.[16]Itisproposedthatmelatoninplaysaroleasanantioxidantintheplacenta.[16] Thisbeginsatday17-day22[17] Birth[edit] Mainarticle:Placentalexpulsion Placentalexpulsionbeginsasaphysiologicalseparationfromthewalloftheuterus.Theperiodfromjustafterthechildisbornuntiljustaftertheplacentaisexpellediscalledthe"thirdstageoflabor".Theplacentaisusuallyexpelledwithin15–30 minutesofbirth. Placentalexpulsioncanbemanagedactively,forexamplebygivingoxytocinviaintramuscularinjectionfollowedbycordtractiontoassistindeliveringtheplacenta.Alternatively,itcanbemanagedexpectantly,allowingtheplacentatobeexpelledwithoutmedicalassistance.Bloodlossandtheriskofpostpartumbleedingmaybereducedinwomenofferedactivemanagementofthethirdstageoflabour,howevertheremaybeadverseeffectsandmoreresearchisnecessary.[18] Thehabitistocutthecordimmediatelyafterbirth,butitistheorisedthatthereisnomedicalreasontodothis;onthecontrary,itistheorisedthatnotcuttingthecordhelpsthebabyinitsadaptationtoextrauterinelife,especiallyinpreterminfants.[19] Microbiome[edit] Mainarticle:Placentalmicrobiome Theplacentaistraditionallythoughttobesterile,butrecentresearchsuggeststhataresident,non-pathogenic,anddiversepopulationofmicroorganismsmaybepresentinhealthytissue.However,whetherthesemicrobesexistorareclinicallyimportantishighlycontroversialandisthesubjectofactiveresearch.[20][21][22][23] Functions[edit] Nutritionandgasexchange[edit] Maternalsideofaplacentashortlyafterbirth. Theplacentaintermediatesthetransferofnutrientsbetweenmotherandfetus.Theperfusionoftheintervillousspacesoftheplacentawithmaternalbloodallowsthetransferofnutrientsandoxygenfromthemothertothefetusandthetransferofwasteproductsandcarbondioxidebackfromthefetustothematernalblood.Nutrienttransfertothefetuscanoccurviabothactiveandpassivetransport.[24]Placentalnutrientmetabolismwasfoundtoplayakeyroleinlimitingthetransferofsomenutrients.[25]Adversepregnancysituations,suchasthoseinvolvingmaternaldiabetesorobesity,canincreaseordecreaselevelsofnutrienttransportersintheplacentapotentiallyresultinginovergrowthorrestrictedgrowthofthefetus.[26] Animatedschematicoftheheartsandcirculatorysystemsofafetusanditsmother–redandbluerepresentoxygenatedanddeoxygenatedblood,respectively(animation) Excretion[edit] Wasteproductsexcretedfromthefetussuchasurea,uricacid,andcreatininearetransferredtothematernalbloodbydiffusionacrosstheplacenta. Immunity[edit] Theplacentafunctionsasaselectivebarrierbetweenmaternalandfetalcells,preventingmaternalblood,proteinsandmicrobes(includingbacteriaandmostviruses)fromcrossingthematernal-fetalbarrier.[27] Deteriorationinplacentalfunctioning,referredtoasplacentalinsufficiency,mayberelatedtomother-to-childtransmissionofsomeinfectiousdiseases.[28] Averysmallnumberofvirusesincludingrubellavirus,Zikavirusandcytomegalovirus(CMV)cantravelacrosstheplacentalbarrier,generallytakingadvantageofconditionsatcertaingestationalperiodsastheplacentadevelops.CMVandZikatravelfromthematernalbloodstreamviaplacentalcellstothefetalbloodstream.[27][29][30][31] Beginningasearlyas13weeksofgestation,andincreasinglinearly,withthelargesttransferoccurringinthethirdtrimester,IgGantibodiescanpassthroughthehumanplacenta,providingprotectiontothefetusinutero.[32][33] Thispassiveimmunitylingersforseveralmonthsafterbirth,providingthenewbornwithacarboncopyofthemother'slong-termhumoralimmunitytoseetheinfantthroughthecrucialfirstmonthsofextrauterinelife.IgMantibodies,becauseoftheirlargersize,cannotcrosstheplacenta,[34]onereasonwhyinfectionsacquiredduringpregnancycanbeparticularlyhazardousforthefetus.[35] Endocrinefunction[edit] Thefirsthormonereleasedbytheplacentaiscalledthehumanchorionicgonadotropinhormone.ThisisresponsibleforstoppingtheprocessattheendofmenseswhentheCorpusluteumceasesactivityandatrophies.IfhCGdidnotinterruptthisprocess,itwouldleadtospontaneousabortionofthefetus.Thecorpusluteumalsoproducesandreleasesprogesteroneandestrogen,andhCGstimulatesittoincreasetheamountthatitreleases.hCGistheindicatorofpregnancythatpregnancytestslookfor.Thesetestswillworkwhenmenseshasnotoccurredorafterimplantationhashappenedondaysseventoten.hCGmayalsohaveananti-antibodyeffect,protectingitfrombeingrejectedbythemother'sbody.hCGalsoassiststhemalefetusbystimulatingthetestestoproducetestosterone,whichisthehormoneneededtoallowthesexorgansofthemaletogrow. Progesteronehelpstheembryoimplantbyassistingpassagethroughthefallopiantubes.Italsoaffectsthefallopiantubesandtheuterusbystimulatinganincreaseinsecretionsnecessaryforfetalnutrition.Progesterone,likehCG,isnecessarytopreventspontaneousabortionbecauseitpreventscontractionsoftheuterusandisnecessaryforimplantation. Estrogenisacrucialhormoneintheprocessofproliferation.Thisinvolvestheenlargementofthebreastsanduterus,allowingforgrowthofthefetusandproductionofmilk.Estrogenisalsoresponsibleforincreasedbloodsupplytowardstheendofpregnancythroughvasodilation.Thelevelsofestrogenduringpregnancycanincreasesothattheyarethirtytimeswhatanon-pregnantwomanmid-cyclesestrogenlevelwouldbe. Humanplacentallactogenisahormoneusedinpregnancytodevelopfetalmetabolismandgeneralgrowthanddevelopment.HumanplacentallactogenworkswithGrowthhormonetostimulateInsulin-likegrowthfactorproductionandregulatingintermediarymetabolism.Inthefetus,hPLactsonlactogenicreceptorstomodulateembryonicdevelopment,metabolismandstimulateproductionofIGF,insulin,surfactantandadrenocorticalhormones.hPLvaluesincreasewithmultiplepregnancies,intactmolarpregnancy,diabetesandRhincompatibility.Theyaredecreasedwithtoxemia,choriocarcinoma,andPlacentalinsufficiency.[36][37] Immunologicalbarrier[edit] Furtherinformation:Immunetoleranceinpregnancy Theplacentaandfetusmayberegardedasaforeignbodyinsidethemotherandmustbeprotectedfromthenormalimmuneresponseofthemotherthatwouldcauseittoberejected.Theplacentaandfetusarethustreatedassitesofimmuneprivilege,withimmunetolerance. Forthispurpose,theplacentausesseveralmechanisms: ItsecretesNeurokinin B-containingphosphocholinemolecules.Thisisthesamemechanismusedbyparasiticnematodestoavoiddetectionbytheimmunesystemoftheirhost.[38] ThereispresenceofsmalllymphocyticsuppressorcellsinthefetusthatinhibitmaternalcytotoxicT cellsbyinhibitingtheresponsetointerleukin 2.[39] However,thePlacentalbarrierisnotthesolemeanstoevadetheimmunesystem,asforeignfetalcellsalsopersistinthematernalcirculation,ontheothersideoftheplacentalbarrier.[40] Other[edit] Theplacentaalsoprovidesareservoirofbloodforthefetus,deliveringbloodtoitincaseofhypotensionandviceversa,comparabletoacapacitor.[41] Ultrasoundimageofhumanplacentaandumbilicalcord(colorDopplerrendering)withcentralcordinsertionandthreeumbilicalvessels,at20weeksofpregnancy Clinicalsignificance[edit] Mainarticle:Placentaldisease Micrographofacytomegalovirus(CMV)infectionoftheplacenta(CMVplacentitis).ThecharacteristiclargenucleusofaCMV-infectedcellisseenoff-centreatthebottom-rightoftheimage.H&E stain. Numerouspathologiescanaffecttheplacenta. Placentaaccreta,whentheplacentaimplantstoodeeply,allthewaytotheactualmuscleofuterinewall(withoutpenetratingit) Placentapraevia,whentheplacementoftheplacentaistooclosetoorblocksthecervix Placentalabruption/abruptioplacentae,prematuredetachmentoftheplacenta Placentitis,inflammationoftheplacenta,suchasbyTORCHinfections. Societyandculture[edit] Theplacentaoftenplaysanimportantroleinvariouscultures,withmanysocietiesconductingritualsregardingitsdisposal.IntheWesternworld,theplacentaismostoftenincinerated.[42] Someculturesburytheplacentaforvariousreasons.TheMāoriofNewZealandtraditionallyburytheplacentafromanewbornchildtoemphasizetherelationshipbetweenhumansandtheearth.[43]Likewise,theNavajoburytheplacentaandumbilicalcordataspeciallychosensite,[44]particularlyifthebabydiesduringbirth.[45]InCambodiaandCostaRica,burialoftheplacentaisbelievedtoprotectandensurethehealthofthebabyandthemother.[46]Ifamotherdiesinchildbirth,theAymaraofBoliviaburytheplacentainasecretplacesothatthemother'sspiritwillnotreturntoclaimherbaby'slife.[47] Theplacentaisbelievedbysomecommunitiestohavepoweroverthelivesofthebabyoritsparents.TheKwakiutlofBritishColumbiaburygirls'placentastogivethegirlskillindiggingclams,andexposeboys'placentastoravenstoencouragefuturepropheticvisions.InTurkey,theproperdisposaloftheplacentaandumbilicalcordisbelievedtopromotedevoutnessinthechildlaterinlife.InTransylvania,andJapan,interactionwithadisposedplacentaisthoughttoinfluencetheparents'futurefertility.[citationneeded] Severalculturesbelievetheplacentatobeorhavebeenalive,oftenarelativeofthebaby.Nepalesethinkoftheplacentaasafriendofthebaby;theorangAsliandMalaypopulationsinMalayPeninsularegarditasthebaby'soldersibling.[46][48]NativeHawaiiansbelievethattheplacentaisapartofthebaby,andtraditionallyplantitwithatreethatcanthengrowalongsidethechild.[42]VariousculturesinIndonesia,suchasJavanese,believethattheplacentahasaspiritandneedstobeburiedoutsidethefamilyhouse.SomeMalayswouldburythebaby'splacentawithapencil(ifitisaboy)oraneedleandthread(ifitisagirl).[48] Insomecultures,theplacentaiseaten,apracticeknownasplacentophagy.Insomeeasterncultures,suchasChina,thedriedplacenta(ziheche紫河车,literally"purplerivercar")isthoughttobeahealthfulrestorativeandissometimesusedinpreparationsoftraditionalChinesemedicineandvarioushealthproducts.[49]Thepracticeofhumanplacentophagyhasbecomeamorerecenttrendinwesternculturesandisnotwithoutcontroversy;itspracticebeingconsideredcannibalismisdebated. Somecultureshavealternativeusesforplacentathatincludethemanufacturingofcosmetics,pharmaceuticalsandfood.[citationneeded] Additionalimages[edit] Fetusofabout8 weeks,enclosedintheamnion.Magnifiedalittleovertwodiameters. Placentawithattachedfetalmembranes,rupturedatthemarginattheleftintheimage. Micrographofaplacentalinfection(CMVplacentitis). MicrographofCMV placentitis. A3DPowerdopplerimageofvasculaturein20-weekplacenta Schematicviewoftheplacenta Maternalsideofawholehumanplacenta,justafterbirth Fetalsideofsameplacenta Close-upofumbilicalattachmenttofetalsideoffreshlydeliveredplacenta Placentaweightbygestationalage[50] Ziheche(紫河车),driedhumanplacentausedintraditionalChinesemedicine Seealso[edit] Choriovitellineplacenta Caul Zygote Pregnancyinfish References[edit] ^Pough,F.H.;Andrews,RobinM.;Cadle,JohnE.;Crump,MarthaL.;Savitsky,AlanH.;Wells,KentwoodD.(2004).Herpetology(3rd ed.).Pearson.ISBN 978-0-13-100849-6.[page needed] ^Mitra,Avir(31January2020)."Howtheplacentaevolvedfromanancientvirus".WHYY.Retrieved9March2020. ^Chuong,EdwardB.(9October2018)."Theplacentagoesviral:Retrovirusescontrolgeneexpressioninpregnancy".PLOSBiology.16(10):e3000028.doi:10.1371/journal.pbio.3000028.PMC 6177113.PMID 30300353. ^Villarreal,LuisP.(January2016)."Virusesandtheplacenta:theessentialvirusfirstview".APMIS.124(1–2):20–30.doi:10.1111/apm.12485.PMID 26818259.S2CID 12042851. ^HenryGeorgeLiddell,RobertScott,"AGreek-EnglishLexicon",atPerseusArchived2012-04-05attheWaybackMachine. ^"placenta"Archived2016-01-30attheWaybackMachine.OnlineEtymologyDictionary. ^Bowen,R.ImplantationandDevelopmentofthePlacenta:IntroductionandIndex.From:PathophysiologyoftheReproductiveSystem.Accessed:7July2019. ^ExaminationoftheplacentaArchived2011-10-16attheWaybackMachine ^PlacentalStructureandClassificationArchived2016-02-11attheWaybackMachine ^Fujikura,Toshio;Benson,RalphC;Driscoll,ShirleyG;et al.(1970),"Thebipartiteplacentaanditsclinicalfeatures",AmericanJournalofObstetricsandGynecology,107(7):1013–1017,doi:10.1016/0002-9378(70)90621-6,PMID 5429965,Bipartiteplacentarepresented4.2percent(366of8,505)ofplacentasofwhitewomenattheBostonHospitalforWomenwhowereenrolledintheCollaborativeProject. ^"Thehumanproteomeinplacenta-TheHumanProteinAtlas".www.proteinatlas.org.Archivedfromtheoriginalon2017-09-26.Retrieved2017-09-26. ^Uhlén,Mathias;Fagerberg,Linn;Hallström,BjörnM.;Lindskog,Cecilia;Oksvold,Per;Mardinoglu,Adil;Sivertsson,Åsa;Kampf,Caroline;Sjöstedt,Evelina(2015-01-23)."Tissue-basedmapofthehumanproteome".Science.347(6220):1260419.doi:10.1126/science.1260419.ISSN 0036-8075.PMID 25613900.S2CID 802377. ^Dashe,JodiS.;Bloom,StevenL.;Spong,CatherineY.;Hoffman,BarbaraL.(2018).WilliamsObstetrics.McGrawHillProfessional.ISBN 978-1-259-64433-7.[page needed] ^PlacentalbloodcirculationArchived2011-09-28attheWaybackMachine ^abKiserudT,AcharyaG(2004)."Thefetalcirculation".PrenatalDiagnosis.24(13):1049–1059.doi:10.1002/pd.1062.PMID 15614842.S2CID 25040285. ^abReiter,R.J.;Tan,D.X.;Korkmaz,A.;Rosales-Corral,S.A.(2013)."Melatoninandstablecircadianrhythmsoptimizematernal,placentalandfetalphysiology".HumanReproductionUpdate.20(2):293–307.doi:10.1093/humupd/dmt054.ISSN 1355-4786.PMID 24132226. ^Williamsbookofobsteritcis. ^Begley,CM;Gyte,GM;Devane,D;McGuire,W;Weeks,A;Biesty,LM(13February2019)."Activeversusexpectantmanagementforwomeninthethirdstageoflabour".CochraneDatabaseofSystematicReviews.2:CD007412.doi:10.1002/14651858.CD007412.pub5.PMC 6372362.PMID 30754073. ^MercerJS,VohrBR,Erickson-OwensDA,PadburyJF,OhW(2010)."Seven-monthdevelopmentaloutcomesofverylowbirthweightinfantsenrolledinarandomizedcontrolledtrialofdelayedversusimmediatecordclamping".JournalofPerinatology.30(1):11–6.doi:10.1038/jp.2009.170.PMC 2799542.PMID 19847185. ^Perez-Muñoz,MariaElisa;Arrieta,Marie-Claire;Ramer-Tait,AmandaE.;Walter,Jens(2017)."Acriticalassessmentofthe"sterilewomb"and"inuterocolonization"hypotheses:implicationsforresearchonthepioneerinfanticrobiome".Microbiome.5(1):48.doi:10.1186/s40168-017-0268-4.ISSN 2049-2618.PMC 5410102.PMID 28454555. ^Mor,Gil;Kwon,Ja-Young(2015)."Trophoblast-microbiomeinteraction:anewparadigmonimmuneregulation".AmericanJournalofObstetricsandGynecology.213(4):S131–S137.doi:10.1016/j.ajog.2015.06.039.ISSN 0002-9378.PMC 6800181.PMID 26428492. ^Prince,AmandaL.;Antony,KathleenM.;Chu,DerrickM.;Aagaard,KjerstiM.(2014)."Themicrobiome,parturition,andtimingofbirth:morequestionsthananswers".JournalofReproductiveImmunology.104–105:12–19.doi:10.1016/j.jri.2014.03.006.ISSN 0165-0378.PMC 4157949.PMID 24793619. ^Hornef,M;Penders,J(2017)."Doesaprenatalbacterialmicrobiotaexist?".MucosalImmunology.10(3):598–601.doi:10.1038/mi.2016.141.PMID 28120852. ^WrightC,SibleyCP(2011)."PlacentalTransferinHealthandDisease".InKayH,NelsonM,YupingW(eds.).ThePlacenta:FromDevelopmenttoDisease.JohnWileyandSons.pp. 66.ISBN 978-1-4443-3366-4. ^PerazzoloS,HirschmuglB,WadsackC,DesoyeG,LewisRM,SengersBG(February2017)."Theinfluenceofplacentalmetabolismonfattyacidtransfertothefetus".J.LipidRes.58(2):443–454.doi:10.1194/jlr.P072355.PMC 5282960.PMID 27913585. ^KappenC,KrugerC,MacGowanJ,SalbaumJM(2012)."Maternaldietmodulatesplacentagrowthandgeneexpressioninamousemodelofdiabeticpregnancy".PLOSONE.7(6):e38445.Bibcode:2012PLoSO...738445K.doi:10.1371/journal.pone.0038445.PMC 3372526.PMID 22701643. ^abMadhusoodanan,Jyoti(October10,2018)."Breakonthrough:Howsomevirusesinfecttheplacenta".KnowableMagazine.doi:10.1146/knowable-101018-1.CS1maint:dateandyear(link) ^Erlebacher,Adrian(2013-03-21)."ImmunologyoftheMaternal-FetalInterface".AnnualReviewofImmunology.31(1):387–411.doi:10.1146/annurev-immunol-032712-100003.PMID 23298207.Retrieved25June2021. ^Pereira,Lenore(2018-09-29)."CongenitalViralInfection:TraversingtheUterine-PlacentalInterface".AnnualReviewofVirology.5(1):273–299.doi:10.1146/annurev-virology-092917-043236.PMID 30048217.Retrieved24June2021. ^Arora,Nitin;Sadovsky,Yoel;Dermody,TerenceS.;Coyne,CarolynB.(May2017)."MicrobialVerticalTransmissionduringHumanPregnancy".CellHost&Microbe.21(5):561–567.doi:10.1016/j.chom.2017.04.007.PMC 6148370.PMID 28494237. ^Robbins,JenniferR;Bakardjiev,AnnaI(February2012)."Pathogensandtheplacentalfortress".CurrentOpinioninMicrobiology.15(1):36–43.doi:10.1016/j.mib.2011.11.006.PMC 3265690.PMID 22169833. ^Palmeira,Patricia;Quinello,Camila;Silveira-Lessa,AnaLúcia;Zago,CláudiaAugusta;Carneiro-Sampaio,Magda(2012)."IgGPlacentalTransferinHealthyandPathologicalPregnancies".ClinicalandDevelopmentalImmunology.2012:985646.doi:10.1155/2012/985646.PMC 3251916.PMID 22235228. ^SimisterN.E.,StoryC.M.(1997)."HumanplacentalFcreceptorsandthetransmissionofantibodiesfrommothertofetus".JournalofReproductiveImmunology.37(1):1–23.doi:10.1016/s0165-0378(97)00068-5.PMID 9501287. ^Pillitteri,Adele(2009).MaternalandChildHealthNursing:CareoftheChildbearingandChildrearingFamily.Hagerstwon,MD:LippincottWilliams&Wilkins.p. 202.ISBN 978-1-58255-999-5. ^"Whatinfectionscanaffectpregnancy?".NationalInstituteofChildHealthandHumanDevelopment.Retrieved25June2021. ^HandwergerS,FreemarkM(2000)."Therolesofplacentalgrowthhormoneandplacentallactogenintheregulationofhumanfetalgrowthanddevelopment".JournalofPediatricEndocrinology&Metabolism.13(4):343–56.doi:10.1515/jpem.2000.13.4.343.PMID 10776988.S2CID 28778529. ^"HumanPlacentalLactogen".www.ucsfhealth.org.May17,2009.ArchivedfromtheoriginalonApril29,2017.RetrievedJuly21,2017. ^"Placenta'foolsbody'sdefences'".BBCNews.10November2007.Archivedfromtheoriginalon29April2012. ^ClarkDA,ChaputA,TuttonD(March1986)."Activesuppressionofhost-vs-graftreactioninpregnantmice.VII.SpontaneousabortionofallogeneicCBA/JxDBA/2fetusesintheuterusofCBA/Jmicecorrelateswithdeficientnon-Tsuppressorcellactivity".J.Immunol.136(5):1668–75.PMID 2936806. ^WilliamsZ,ZepfD,LongtineJ,AnchanR,BroadmanB,MissmerSA,HornsteinMD(March2008)."Foreignfetalcellspersistinthematernalcirculation".Fertil.Steril.91(6):2593–5.doi:10.1016/j.fertnstert.2008.02.008.PMID 18384774. ^AssadRS,LeeFY,HanleyFL(2001)."Placentalcomplianceduringfetalextracorporealcirculation".JournalofAppliedPhysiology.90(5):1882–1886.doi:10.1152/jappl.2001.90.5.1882.PMID 11299282. ^ab"Whyeataplacenta?".BBCNews.18April2006. ^Metge,Joan(2005)."WorkingIn/PlayingWithThreeLanguages".Sites:AJournalofSocialAnthropologyandCulturalStudies.2(2):83–90.doi:10.11157/sites-vol2iss2id65. ^Francisco,Edna(3December2004)."BridgingtheCulturalDivideinMedicine".Science. ^Shepardson,Mary(1978)."ChangesinNavajomortuarypracticesandbeliefs".AmericanIndianQuarterly.4(4):383–96.doi:10.2307/1184564.JSTOR 1184564.PMID 11614175. ^abBuckley,SarahJ."PlacentaRitualsandFolklorefromaroundtheWorld".Mothering.Archivedfromtheoriginalon6January2008.Retrieved7January2008. ^Davenport,Ann(June2005)."TheLoveOffer".JohnsHopkinsMagazine.57(3). ^abAnisahBarakbah(2017).EnsiklopediaPerbidananMelayu.UniversitiIslamMalaysiaPress.pp. 236–237.ISBN 978-967-13305-9-3. ^Falcao,Ronnie."MedicinalUsesofthePlacenta".Archivedfromtheoriginalon5December2008.Retrieved25November2008. ^"PlacentalWeights:Means,StandardDeviations,andPercentilesbyGestationalAge".PlacentalandGestationalPathology.2017.p. 336.doi:10.1017/9781316848616.039.ISBN 978-1-316-84861-6. Externallinks[edit] WikimediaCommonshasmediarelatedtoPlacenta. LookupplacentainWiktionary,thefreedictionary. Theplacenta-specificproteomeattheHumanProteinAtlas ThePlacenta,gynob.com,withquotesfromWilliamsObstetrics,18thEdition,F.GaryCunningham,M.D.,PaulC.MacDonald,M.D.,NormanF.Grant,M.D.,Appleton&Lange,Publishers. vteMembranesofthefetusandembryoEmbryo Trophoblast Cytotrophoblast Syncytiotrophoblast Intermediatetrophoblast Allantois Decidua Decidualcells Chorionicvilli/Intervillousspace Amnion sac cavity Fetus Umbilicalcord Umbilicalartery Umbilicalvein Wharton'sjelly Circulatory Placenta Chorion Other Blastocoel Heuser'smembrane Vitellineduct Gestationalsac vteDevelopmentofthecirculatorysystemHeartTubularheart Truncusarteriosus Bulbuscordis Primitiveventricle Primitiveatrium Sinusvenosus Chamberformation Atrioventricular Primaryinterventricularforamen Endocardialcushions Septumintermedium Atrioventricularcanal Atrial Septumprimum Foramensecundum Primaryinteratrialforamen Septumsecundum Foramenovale Other Aorticopulmonaryseptum Proteinsignallinginheartdevelopment VesselsArteries Dorsalaorta Aorticarches Aorticsac Veins Anteriorcardinalvein Posteriorcardinalvein Commoncardinalveins Lymphvessels Lymphsacs Other Vascularremodellingintheembryo Extraembryonichemangiogenesis Bloodislands Chorion Connectingstalk Yolksac Placenta Fetalcirculation umbilicalcord:Umbilicalvein→Ductusvenosus→Inferiorvenacava→Heart→Pulmonaryartery→Ductusarteriosus→Aorta→Umbilicalartery yolksac:Vitellineveins Vitellinearteries AuthoritycontrolGeneral IntegratedAuthorityFile(Germany) Nationallibraries Spain France(data) UnitedStates Japan Other MicrosoftAcademic 2 3 Retrievedfrom"https://en.wikipedia.org/w/index.php?title=Placenta&oldid=1057400672" Categories:VertebratedevelopmentalbiologyEmbryologyofcardiovascularsystemOrgans(anatomy)ReproductivesystemMicrobiomesHumanfemaleendocrinesystemHiddencategories:WikipediaarticlesneedingpagenumbercitationsfromAugust2021WebarchivetemplatewaybacklinksCS1:longvolumevalueCS1maint:dateandyearArticleswithshortdescriptionShortdescriptionisdifferentfromWikidataAllarticleswithunsourcedstatementsArticleswithunsourcedstatementsfromJanuary2021ArticleswithunsourcedstatementsfromAugust2021CommonscategorylinkisonWikidataArticleswithGNDidentifiersArticleswithBNEidentifiersArticleswithBNFidentifiersArticleswithLCCNidentifiersArticleswithNDLidentifiersArticleswithMAidentifiersArticleswithmultipleidentifiers Navigationmenu Personaltools NotloggedinTalkContributionsCreateaccountLogin Namespaces ArticleTalk Variants expanded collapsed Views ReadEditViewhistory More expanded collapsed Search Navigation MainpageContentsCurrenteventsRandomarticleAboutWikipediaContactusDonate Contribute HelpLearntoeditCommunityportalRecentchangesUploadfile Tools WhatlinkshereRelatedchangesUploadfileSpecialpagesPermanentlinkPageinformationCitethispageWikidataitem Print/export DownloadasPDFPrintableversion Inotherprojects WikimediaCommons Languages AfrikaansالعربيةܐܪܡܝܐAvañe'ẽAymararuAzərbaycancaবাংলাБеларускаяБеларуская(тарашкевіца)БългарскиBosanskiCatalàЧӑвашлаČeštinaCymraegDanskDeutschދިވެހިބަސްEestiΕλληνικάEmiliànerumagnòlEspañolEsperantoEuskaraفارسیFrançaisGaeilgeGalego한국어Հայերենहिन्दीHrvatskiBahasaHulontaloIdoBahasaIndonesiaÍslenskaItalianoעבריתJawaಕನ್ನಡქართულიҚазақшаKreyòlayisyenКыргызчаLatinaLatviešuLietuviųLiNihaLigureMagyarМакедонскиമലയാളംमराठीBahasaMelayuNederlands日本語NorskbokmålNorsknynorskOccitanپنجابیPolskiPortuguêsRomânăRunaSimiРусскийSakizayaScotsShqipSimpleEnglishسنڌيSlovenščinaکوردیСрпски/srpskiSrpskohrvatski/српскохрватскиSundaSuomiSvenskaTagalogதமிழ்TaqbaylitతెలుగుไทยTürkçeУкраїнськаاردوTiếngViệtWinaray吴语粵語中文 Editlinks