獸醫(yī)產(chǎn)科學(xué) 第四章 妊娠課件

第四章

妊娠

ChapterFourGestation第一節(jié)妊娠期LessonOneGestationPeriod妊娠：受精卵在母畜子宮內(nèi)附植直至分娩的過程叫妊娠。Gestation:Aprocessthatthezygoteenclosedplantindamuterusuntildeliverycalledgestation.妊娠期：最后一次配種直至分娩為止所經(jīng)歷的時(shí)間。GestationPeriod:Thetimeexperiencedfromthelastmatingtodelivery.一、動(dòng)物的妊娠期

Partone.Gestationperiodoftheanimal牛：280天9.5個(gè)月水牛：307天10個(gè)月Bovine:280days9.5monthsbuffalo:307days10months馬：340天11個(gè)月馬懷騾：330天11個(gè)月Horse:340days11monthsmule:330days11months驢：360天12個(gè)月羊：150天5個(gè)月Neddy:360days12monthssheep:150days5months豬：114天3個(gè)月狗：62天2個(gè)月Swein:114days3monthsDog:62days2months貓：58天2個(gè)月兔：30天1個(gè)月Cat:58days2monthsHare:30days1months

懷孕期簡(jiǎn)易推算法Simplemethodsofestimatingpregnancy

牛：配種月份減3，配種日期加10Bovine:themattingmonthdecrease3,themattingdate羊：＝＝＝＝加5，＝＝＝＝減2

sheep:＝＝＝＝add5，＝＝＝＝decrease2豬：＝＝＝＝加4，＝＝＝＝減10

Swein:＝＝＝＝add4，＝＝＝＝decrease10馬：＝＝＝＝減1，＝＝＝＝加10

Horse:＝＝＝＝decrease1，＝＝＝＝add10二、影響妊娠期的因素Parttwo.Influencefactorsofgestation（一）遺傳因素SectionOne.Geneticfactor（二）胎兒數(shù)目和性別因素SectionTwo.Fetalnumberandgenderfactors

多胎懷胎數(shù)少時(shí)，妊娠期變長(zhǎng)WhentheMultiplebirthsnumberisfew,pregnantgestationalgrowlonger單胎懷雙胎，胎兒為雌性，青年母畜比老齡母畜妊娠期縮短。Ifthemonotocousanimalhadtwinsandthefetusisfemale,thegestationofyoungfemalelivestockisshorterthantheoldfemalelivestock’s.（三）營養(yǎng)水平及疾病因素SectionThree.Nutritionlevelanddiseasefactors

1.使妊娠期縮短的因素1.Factorsmakegestationshorten營養(yǎng)不良、慢性疾病、強(qiáng)應(yīng)激。Malnutrition,chronicdiseasesandstrongstress.第二節(jié)母體的妊娠識(shí)別

LessonTwoMaternalrecognitionofpregnancy

一、妊娠識(shí)別Partone.Recognitionofpregnancy

胚胎與母體子宮從免疫學(xué)、細(xì)胞生物學(xué)、內(nèi)分泌學(xué)等方面相互作用的過程。Aprocessofembryosandthematernaluterusinteractfromimmunology,cellbiologyandendocrinologyaspects.二、妊娠建立Parttwo.Establishofpregnancy

繼妊娠識(shí)別后，母子產(chǎn)生信息和物質(zhì)交換，妊娠得以維持的現(xiàn)象。Aphenomenonthattheinformationandmaterialexchangefrommotherandgenerateafterrecognitionofpregnancywhichmakesthepregnancymaintained.維持妊娠的主要激素是孕酮，來源于黃體和胎盤。Themainlyhormoneformaintainingthepregnancyisprogesterone,whichoriginatefromcorpusluteumandtheplacenta.三、妊娠識(shí)別與建立的時(shí)間Partthree.Thetimeofrecognitionandestablishofpregnancy

畜別妊娠識(shí)別妊娠建立genderoflivestockrecognitionofpregnancyestablishofpregnancy牛16-17d18-22dbovine16-17d18-22d羊12-13d16dsheep12-13d16d豬12d18dpig12d18d馬14-16d36-38dhorse14-16d36-38d

四、動(dòng)物妊娠識(shí)別機(jī)理PartFour.Mechanismofrecognitionofanimalpregnancy（一）反芻動(dòng)物SectionOne.Ruminantanimals

滋養(yǎng)層蛋白-1（IFN-τ，interferon-τ)通過抑制PGs分泌、OT和E受體合成，促進(jìn)黃體孕酮的分泌，維持妊娠。Trophoblasticprotein-1(IFN-τ,interferon-τ)byinhibitingsecretionofPGsandsynthesisofOTandEreceptor,promotingsecretionofcorpusluteumprogesteronetomaintainpregnancy.（二）豬SectionTwo.Pigs

滋養(yǎng)外胚層產(chǎn)生雌二醇和雌酮，轉(zhuǎn)變成硫酸雌酮，使子宮內(nèi)膜PGs合成減少，并阻止其進(jìn)入子宮靜脈，黃體得以維持。Nourishoutsidemesodermproduceoestrogenandfemaleketones,thenchangethemintosulfuricacidfemaleketones,makethesynthesisofendometrialPGsdecreasesandpreventsitintotheuterusvein,socorpusluteinismaintained.（三）馬SectionThree.Horses與豬相似。Similartothepig.（四）靈長(zhǎng)類SectionFour.Primates

囊胚的合胞體滋養(yǎng)層產(chǎn)生hCG，抑制溶黃物質(zhì)的作用。ThesyncytialtrophoblastofblastosphereproducehCG,restrainthefunctionofthesubstancethatdissolveCorpusluteum.

hCG是在排卵后7-10天可以從血漿中測(cè)出，因此可用作早孕診斷。hCGcanbemeasuredfromplasmain7to10daysafterovulation,soitcanbeusedtodiagnosingearlypregnancies.一、胚胎早期發(fā)育

PartOne.Earlyembryonicdevelopment1．卵裂球：1.blastomere合子形成后若干天內(nèi)連續(xù)進(jìn)行的間接分裂，稱為卵裂。這時(shí)的胚胎稱卵裂球。（見圖）cleavageisthecontinuationofindirectsplitinseveraldaysafterzygoteformed.theembryosinthistimenamedblastomere.(chart)合子一邊沿輸卵管下移，一邊開始分裂。Azygotemovedownalongthetubal,andbegantosplit.2．桑椹胚：2.morula當(dāng)卵子分裂為16－32個(gè)細(xì)胞時(shí)，細(xì)胞形成一團(tuán)形，很象桑椹故稱。但仍在透明帶包圍之中。Whenovumsplitsinto16-32cells,cellsformingagroupform,muchlikethemulberrythereforecallsmorula.Butstillinsurroundedbysheertape.3．囊胚：3.blastosphere當(dāng)桑椹胚中央出現(xiàn)空泡時(shí)，細(xì)胞出現(xiàn)分化：Whenemptybubbleappearsinthecentralofmorula,cellsbegantodifferentiation:外圍：較小的細(xì)胞，含有吞噬細(xì)胞，稱之“滋養(yǎng)層”細(xì)胞，是以后形成胎衣的部分。Peripheral:smallercells,containingphagocyticcells,calledthe"trophoblastic"cells,whichisformedpartofafterbirthlateron.內(nèi)團(tuán)：較大的細(xì)胞，稱“胚結(jié)”，是以后形成胚胎的原始部分。Withingroup:largercells,called"embryotie",whichisformedtheoriginalpartofembryoslateron.4．胚泡：4.germinalvesicle:囊胚的繼續(xù)發(fā)育，內(nèi)部的空泡充滿液體，并不斷增加，最后突破透明帶，透明帶消失，此時(shí)囊胚就變成了透明的泡狀。Theblastospherecontinuedtodevelop,internalvacuolefilledwithfluid,andescalation,finallyitbreakthetransparentbelt,andtransparentbeltdisappear,nowblastospherebecomesatransparentbubbly.透明帶消失后，胚泡仍在子宮中游離，通過吸收子宮乳中的營養(yǎng)而成活。野生動(dòng)物由于野外條件不同，胚泡游離時(shí)間差異很大，決定了懷孕期長(zhǎng)短。如水貂（37-91天）。afterTransparentbeltdisappeared,agerminalvesicleisstillfreeintheuterus,throughabsorbingnutritionfromthemilk-likeliquidinuterusandsurvive.Duetodifferentfieldconditionsforwildanimals,theirgerminalvesiclehasaverybigdifferenceinfreetime,thisdeterminesthelengthofpregnancy.Likeminks(37-91days).子宮乳成分：上皮細(xì)胞碎片、子宮腺分泌物、淋巴球、血球等。ingredientsofUterinemilk:debrisofepithelialcell,secretionofuterinegland,lymphocytes,bloodcell,etc.5．著床：5.nidation

胚泡在子宮中的位置固定下來，并開始和子宮內(nèi)膜發(fā)生組織上的聯(lián)系，稱為著床。Thegerminalvesicle’spositionintheuteruscometostayandstartorganizationalcontactwithendometrial,calledthenidation.

胚泡形成初期，在子宮內(nèi)呈游離狀態(tài)，以后一方面由于泡腔內(nèi)液體增多，胚泡變大，在子宮內(nèi)的活動(dòng)受到限制，與子宮上皮的接觸變得密切，與母體建立供求關(guān)系；另一方面，子宮乳不能滿足生長(zhǎng)需要而附植下來。著床是一個(gè)漸進(jìn)過程。Atearlyofthegerminalvesicleforming,itisthefreestateintheuterus,Laterononehandbecauseofbubblechamberliquidincreasedandblastocystsgreaten,theactivityisrestrictedintheuterus,andcontactcloselywithuterineepithelia,thenestablishtherelationsbetweensupplyanddemandwithmaternal;Ontheotherhand,uterinemilkcannotsatisfiedtheneedsofgrowthandattachplantdown.Thenidationisagradualprocess.動(dòng)物胚胎著床時(shí)間

ThetimeofAnimalembryonidation牛：12－15天

Bovine:12-15days28－32天開始――到40－45天完成；Startat28-32days――accomplishto40-45days羊：12－20天

Sheep:12-20days14－16天開始――到28－35天完成；Startat14-16days――accomplishto28-35days豬：10－12天

Pig:10-12days14－16天開始――到25－26天完成；Startat14-16days――accomplishto25-26days馬：60－65天

Horse:60-65days35－40天開始――到95－105天完成；Startat35-40days――accomplishto95-105days動(dòng)物胚胎著床部位

ThepositionofAnimalembryonidation

子宮中最有利于發(fā)育的地方開始，如牛、羊，多在子宮角基部開始，向中部發(fā)展。因這里是子宮中動(dòng)脈進(jìn)入子宮的地方，血液供應(yīng)最為豐富。Startattheplacemostfavorabletothedevelopmentintheuterus,suchasbovineandsheep,muchbeganinthebaseofthecornuauterianddevelopmenttothemiddlepart.Becausehereistheplacethattheuterinearteryentertotheuterus,bloodsupplyisthemostabundant.第四節(jié)胎膜和胎盤

LessonFourFetalmembraneandplacenta一、胎膜PartOne.Fetalmembrane叫胚胎外膜，又叫“胎衣”、“胞衣”、“衣胞”等。Callembryonicoutermembranes,alsocalled"afterbirth","secundina","amnia"etc.胎膜主要指羊膜、尿膜、絨毛膜，其構(gòu)造在不同的動(dòng)物有很大的差異。Fetalmembranemainlyreferstotheamnioticmembrane,urinarymembrane,chorion,itsconstructionhaveagreatdifferenceindifferentanimals.牛、羊胎膜囊Fetalmembranes

capsuleofbovineandsheep1．羊膜：是靠近胎兒的一層膜。呈透明狀，包圍胎兒形成羊膜腔；

1.Amnioticmembrane:Itisalayeroffilmnearthefetus.InAtransparentshape,surroundedthefetusandformedamnioticcavity;2．尿膜：可分內(nèi)外兩層，內(nèi)層與羊膜相粘連，外層與絨膜相粘連；2.Urinarymembrane:It

canbedividedintotwolevelstheinsideandoutside,theinnerlayerconglutinatedwiththeamnioticmembrane,theouterlayerconglutinatedwiththechorion.3．絨毛膜：是胎膜的最外層，表面有絨毛，是形成胎盤的基礎(chǔ)。3.Chorion:It

istheoutermostlayerofthefetalmembranes,thesurfaceisvillous,itisthebasisofformingtheplacenta.（一）卵黃囊：由內(nèi)胚層、臟中胚層和滋養(yǎng)層構(gòu)成。是胚胎發(fā)育早期提供營養(yǎng)的器官（起原始胎盤的作用）。SectionOne.Yolksac:Itisconstitutesbytheendoderm,visceralmesodermandtrophoblast.Itistheorgansthatprovidenutritioninearlyofembryonicdevelopment(roleasoriginalplacenta).（二）羊膜囊：羊膜由外胚層（滋養(yǎng)層）和體壁中胚層構(gòu)成，出現(xiàn)在卵黃囊發(fā)育之后，一般在妊娠后13-16天形成。SectionTwo.Amnioticsac:Amnioticmembraneisconstitutesbyectoderm(trophoblastic)andthesomaticmesoderm,whichappearsaftertheyolk-sacdevelopment,andformscommonlyat13-16daysaftergestation.（三）尿膜囊：尿膜囊壁由中胚層的血管層覆蓋在內(nèi)胚層上構(gòu)成的。尿膜囊是沿著臍帶并靠近卵黃囊由后腸發(fā)育而來的一個(gè)外囊。SectionThree.Urinarymembranesac:Urinarymembranebursawallisconstitutesbymesodermalvascularlayercoveringtheendoderm.Urinarymembranesacisalongtheumbilicalcordandclosetotheyolk-sacanditisaoutsidesacthatdevelopsbyposteriorintestine.（四）絨毛膜囊：由外胚層和體壁中胚層構(gòu)成。SectionFour.Chorionicsac:Itisconstitutesbyectodermandsomaticmesoderm.（五）臍帶：由卵黃囊殘跡和卵黃管和延伸而成，是連接胎兒和胎盤的紐帶。SectionFive.Umbilicalcord:

Itisextendbytheremnantsofyolk-sacandyolktube,anditislinktoconnectthefetusandplacenta.二、胎水

PartTwo.Placentalfluid

是羊膜腔里的羊水和尿膜腔內(nèi)的尿水總稱。Itisagenerictermsofamnioticfluidintheamnioticcavityandurinaryfluidintheurinarymembranecavity.1．羊水1.Amnioticfluid來源：①羊膜柱狀上皮細(xì)胞的分泌物；②胎兒唾液腺的分泌物。Sourc:①Thesecretionofcolumnarepithelialcellinamnioticmembrane;

②Thesecretionofthesalivaryglandsinthefetus.顏色：透明粘液狀，后期稍帶濁白色。Color:transparentmuciform,latewithslightlyturbidwhite.

羊水量：牛：5－6升馬：3－7升羊:0.4－1.2升／只豬：40－150毫升／只Contentofamnioticfluid:Bovine:5-6litresHorse:3-7litersSheep:0.4-1.2litres/onlyPig:40-150milliliter/only成分：Ingredients:①混有脫落細(xì)毛，上皮，灰白色的胎餅（豬沒有）。①M(fèi)ixwithfalloffsoftfur,epithelium,gray-whiteembryocake(pigsdonothavethem).②含有微量激素，包括PRL、OT。②Containtracesofhormones,includingPRL,OT.③蛋白酶、淀粉酶、脂解酶。③Protease,amylase,lipidsolutionenzymes.④蛋白質(zhì)、果糖、脂肪、鹽類。④Protein,fructose,fat,salt.3．胎水的作用PartThree.Theeffectofplacentalfluid緩沖作用：使胎兒的身體各部位受壓均勻，不致造成畸形。Bufferaction:makeeachpartsofthefetalbodypressureevenly,withoutcausingdeformity.緩和子宮外來壓迫、撞擊：也可以防止一部分胎盤、子宮壁及臍帶受到胎兒壓迫，而使血液供給障礙。Easeforeignoppressionandbumpofuterine:alsocanpreventpartofoppressionthatplacenta,uterinewallandumbilicalcordsufferfromfetus,andmakeobstaclesofthebloodsupply.羊水可以防止胎兒與周圍組織的粘連。Amnioticfluidcanpreventtheadhesionofthefetusandthesurroundingtissue.分娩時(shí)，子宮壁的收縮，可將胎水推壓到松軟的子宮頸管，從而幫助擴(kuò)大子宮頸管的作用。Whenparturited,theuterinewalliscontracted,anditwillpushpressplacentalfluidtoloosecervicalcanal,thushelpexpandtheeffectofcervicalcanal.天然潤(rùn)滑劑作用：以利胎兒產(chǎn)出。Effectofnaturallubricants:easytothefetaloutput.三、胎盤

PartThree.Placenta胎盤通常指尿膜絨毛膜和子宮粘膜發(fā)生聯(lián)系所形成的構(gòu)造。Placentausuallyreferstothestructurethatformedbythecontactsofurinarymembrane,chorinandtheuterinemucosa.分：胎兒胎盤――尿膜絨毛膜的絨毛部分母體胎盤――子宮粘膜部分Divideinto:fetalplacenta――thevillipartofurinarymembraneandchorion.Maternalplacenta――thepartofuterinemucosa

各自分布自己的血管到自己的胎盤部分，并不直接相通。Theydistributedtheirownbloodvesselstotheirownplacentalpart,andnotdirectlyinterlinked.（一）胎盤的分類

SectionOne.Classifyofplacenta1．按照形態(tài)分1.Accordingtotheform（1）彌散型胎盤(1)Diffuseplacenta

整個(gè)尿膜絨毛膜表面均覆蓋有絨毛，絨毛伸入子宮內(nèi)膜腺窩形成胎盤。電鏡下,絨毛滋養(yǎng)層上皮細(xì)胞核成圓形,核仁大。粗面內(nèi)質(zhì)網(wǎng)發(fā)達(dá)，線粒體豐富。Thewholesurfaceofurinarymembraneandchorionarecoveredwithfluff,andthefluffstretchintoendometrialglandularnestandformedtheplacenta.Underelectronmicroscopy,fluffytrophoblasticepithelialcellsnucleusisroundnessandnucleoliisbig.Roughendoplasmicreticulumisdevelopedandmitochondriaisrich.

代表動(dòng)物:豬、馬、駱駝、鯨、海豚等。Representativeanimal:pigs,horses,camels,whales,dolphins,etc.特點(diǎn)：絨毛和腺窩聯(lián)系雖是緊密的，但不牢固，絨毛在分離時(shí)，不牽連子宮粘膜。Features:Thoughthecontactofvilliandglandularnestisclosely,itisnotfirm.Whenthevilliisinseparation,itdon’tinvolveduterinemucosa.故：①較易發(fā)生流產(chǎn)，尤在懷孕早期；②分娩時(shí)，絨毛膜易脫離，如果胎兒排出緩慢，易發(fā)生窒息；③胎兒排出快，很少發(fā)生胎衣不下。So:①Itismoreeasilyhappentoabortespeciallyinearlypregnancy;②Whenparturited,chorioniseasilytobreakaway.Ifthefetusexpulsedslowly,itiseasilyhappentostifle;③Ifthefetusexpulsedfast,itseldomoccursretentionofafterbirth.（2）子葉型胎盤

(2)Cotyledonstypeplacenta

子宮粘膜上只有子宮阜部分與相應(yīng)的絨毛發(fā)生聯(lián)系。尿膜絨毛上的絨毛亦分別集中形成許多絨毛叢（形成胎兒子葉）。Itwasonlyuterinepartcontactswiththecorrespondingvilliontheuterinemucosa.Thevilliontheurinarymembranearealsoonthecentralizedandformsmanyvilliplexus(formedthefetalcotyledons).無論?；蜓?，子葉之外的區(qū)域不與絨毛發(fā)生任何聯(lián)系（聯(lián)系則為病理狀態(tài)）。Whetherbovineorsheep,theareasoutsidecotyledonshasnotanycontactwithvilli(Ifcontact,itispathologicalstatus).電鏡下，絨毛表面細(xì)胞呈柱狀/不規(guī)則形，核球形，核仁大，細(xì)胞游離面有微絨毛。巨細(xì)胞體積大，核仁明顯，胞質(zhì)豐富，可分泌絨毛促性腺激素。Underelectronmicroscopy,fluffysurfacecellsarecolumnarorirregularform,nuclearisspherical,nucleoliisbig,thefreesurfaceofthecellshavemicrovilli.Giantcellhasbigvolumeandnucleoliisobvious,cytoplasmisrich,itcansecretefluffygonadotropins.

代表動(dòng)物：牛、羊?qū)儆诖祟?。Representativeanimal:bovineandsheeparebelongtothiskind.子葉型胎盤的特點(diǎn)

Thecharacteristicsofthecotyledonstypeplacenta流產(chǎn)要比彌散型胎盤發(fā)生少；Ithaslessabortionthandiffuseplacenta;聯(lián)系緊密，產(chǎn)程長(zhǎng)也不會(huì)造成缺氧而發(fā)生窒息；Therelationisclosely,soifthestagesoflaborislong,itwon'tbehappennedtostiflecausedbyhypoxia;胎衣排出較慢，胎衣不下的比率較高。Afterbirthexpulsedslowly,sotheratiooftheretentionofafterbirthishigher.（3）帶狀胎盤

(3)Thezonaryplacenta

胎兒絨毛膜上的絨毛集中于絨毛膜中央在尿膜絨毛膜上形成環(huán)帶狀，子宮內(nèi)膜上也形成相應(yīng)的帶母體胎盤。Thevilliofthefetalchorionhasfocusedonthecentraofthechorionandformedaringbandingintheurinarymembraneandchorion,anditalsoformedthecorrespondingbandingofthematernalplacentaontheendometria.特點(diǎn)：Characteristics:

分娩時(shí)母體胎盤組織脫落，子宮血管破裂，故有出血現(xiàn)象。Thehemorrhagewillappearbecausewhenparturition,theplacentatissueabscissfromthematrixandthevesseloftheuterinerupture.

代表動(dòng)物：狗、貓。Representativeanimals:Thedogandcat.犬帶狀胎盤zonaryplacentaofdog（4）盤狀胎盤

(4)Discoidplacenta絨毛膜上的絨毛在發(fā)育過程中逐漸集中，局限于一圓形區(qū)域。（絨毛直接侵入子宮內(nèi)膜血竇中，毛上皮由細(xì)胞滋養(yǎng)層和合胞體滋養(yǎng)層構(gòu)成）呈盤狀，故稱盤狀胎盤。Thevillusonchorionconcentratetoonecircleareagradullyduringdevelopment.(Thevillusinvadeintoendometriumsinusoiddirectly,theepitheliumcomposedofcytotrophoblastandplasmoditrophoblast)

Itlookslikeadisk,thereforecalls

discoticplacenta.代表動(dòng)物：見于嚙齒類和靈長(zhǎng)類動(dòng)物，如兔、鼠和人。Representativeanimals:Therodentandprimatesuchasrabbits,mouse,andhuman.2.按母體血液和胎兒血液之間的組織層次分

2.Accordingtotheleveloforganizationbetweenthemotherandchild

（1）上皮絨毛膜型由子宮上皮細(xì)胞和絨毛膜滋養(yǎng)層細(xì)胞接觸形成。物質(zhì)交換經(jīng)六道屏障:(1)

Epithelia-chorialtypeItisformedbythecontactofuterineepithelialcellandchoriontrophoblasts.Tofulfilledtheinterchangeofmaterial,theymustacrosssixbarriers:a.子宮內(nèi)膜上皮endometrialepithelium.b.子宮內(nèi)膜結(jié)締組織endometrialconnetivetissuec.子宮血管內(nèi)皮endometrialvascularepitheliumd.胎兒絨毛膜上皮fetuschorionicepitheliume.絨毛膜間充質(zhì)（結(jié)締組織）connectivetissuef.絨毛膜血管內(nèi)皮chorionvascularendothelium代表動(dòng)物：豬和馬。Representativeanimals:Theswineandhorse.（2）上皮結(jié)締絨毛膜型由子宮結(jié)締組織（子宮上皮在妊娠4個(gè)月以后變性消失）和絨毛膜接觸形成。物質(zhì)交換只經(jīng)過五道屏障.

(2)epithelialconnectiveChorionic-type

Itisformedbythecontactofuterusconnectivetissue(whichwilldisappearafter4monthgestation)andchorion.Itonlyneedfivebarrierstofinishtheinterchangeofmaterial.

代表動(dòng)物：反芻動(dòng)物。

Representativeanimals:Theruminant（3）內(nèi)皮絨毛膜型由子宮血管內(nèi)皮和絨毛接觸形成。物質(zhì)交換經(jīng)過四道屏障.

(3)Theendotheliochorialtype

Itisformedbythecontactofendometrialvascularepitheliumandvillus.Theinterchangeofmaterialneedtoacrossfourbarriers.

代表動(dòng)物：犬、貓。Representativeanimals:Thedogandcat（4）血液絨毛膜型胎兒絨毛直接侵入母體血液血池內(nèi)形成。物質(zhì)交換只經(jīng)過三道屏障.(4)Bloodepithelia-chorialtype

Fetalcotyledoninvadeintomatrixblooddirectly.Theinterchangeofmaterialonlyneedtoacrossthreebarriers.代表動(dòng)物：嚙齒類和靈長(zhǎng)類。Representativeanimals:Therodentandprimate（二）胎盤的生理作用

SectionTwo.Thephysiologicalactionofplacenta胎盤擔(dān)負(fù)著胎兒的消化、呼吸和排泄器官的作用，而且還有內(nèi)分泌機(jī)能。Theplacentashoulderthefunctionofdigestion,breathing,excretionandalsothatofincretion.1．胎盤的隔（屏）障作用：

1.Thebarrierfunctionoftheplacenta:

母子之間物質(zhì)交換，通過胎盤，具有選擇作用。即除了單純性彌散作用外，還能加速彌散或主動(dòng)轉(zhuǎn)運(yùn)作用。Withthehelpoftheplacenta,motherandchildcanfulfilltheinterchangeofmaterial.Theinterchangeofmaterialisselectivebecauseithasnotonlythediffusionfunctionbutalsotheactivetransportfunction.①簡(jiǎn)單的物質(zhì)可以直接通過胎盤：水、Nacl、Cu、I、VB和VC等；①

Thesimplerkindofmattercantransittheplacentadirectly:suchaswater,NaCl,Cu,I,VB,Vcandsoon;②某些物質(zhì)不能直接通過，須經(jīng)過生化改造后才能通過：②

Thefollowingmaterial

cannottransit

theplacentadirectlywithoutthebiochemicalalterations:脂肪→脂肪酸＋甘油蛋白質(zhì)→氨基酸葡萄糖（母體主要糖類）→胎盤轉(zhuǎn)化為果糖（胎兒血糖的70－80％）。Lipid→Fattyacid+GlycerinProtein→AminoacidGlucose(mainlythecarbohydrateinmatrix)→transformintofructosethroughplacenta(70－80％bloodsugaroffetus)③逆滲透梯度通過胎盤：母體血液中的濃度明顯低于胎兒血液。③

Transittheplacentareversetheosmosisgradient:Theconcentrationofmaterialinbloodofmatrixismuchlowerthanthatoffetus.如鈣、磷，如果飼料中含量太低，母體骨髓中的鈣、磷即受損耗，易產(chǎn)生孕畜截癱；Suchascalciumandphosphorus.Thematrixiseasytohavetheparaplegiabecausethecalciumandphosphorusiseasytobelosedwhenthereisnotenoughcalciumandphosphorusinforage.蛋白質(zhì)：通過分解為氨基酸，后逆濃度梯度進(jìn)入胎盤Protein:Afterbeingresolvedintoaminoacid,itransittheplacentareversetheosmosisgradient.④不能通過屏障的：VA、VD、VE等脂溶性維生素。④Thefollowingfat-solublevitaminsuchasVA,VD,VEis

unabletotransittheplacenta.⑤氧氣易通過胎盤進(jìn)入胎兒，二氧化碳則相反易通過胎盤排出；因?yàn)椋ケPpH較低，母體氧化血紅蛋白進(jìn)入胎盤很易離析，胎兒血紅蛋白對(duì)氧有更大的親和力。胎兒血液與二氧化碳的親和力要比母體血液低。⑤

Oxygencantransittheplacentaintofetuseasily,carbondioxide,onthecontrary,easilyexcretedthroughtheplacenta.ItisbecausethatthelowerpHinplacentamadehemoglobineasytodissociatewhentheytransitintotheplacenta,thefetalhemoglobinismoretendtobondtheoxygenbuthaveloweraffinitywithcarbondioxide.⑥某些（對(duì)胎兒發(fā)育有影響）的物質(zhì)也可直接通過：乙醚、氯仿、酒精、樟腦、水楊酸、松節(jié)油、阿托品、毛果蕓香堿、番木氅酊、砷等。⑥Thefollowingmaterial(whichwillinfluencethedevelopmentoffetus)such

asaether,chloroform,alcohol,camphor,BHA,turpentineoil,atropin,picarpineandarsenic

cantransittheplacentadirectly.⑦細(xì)菌不能通過，病毒可通過：但當(dāng)胎盤病變時(shí)，細(xì)菌也能通過；⑦Theviruscantransittheplacentawhilethebacteriacan’t:Butwhenplacentaispathologicalchanges,thebacteriacanalsotransittheplacenta.⑧部分抗體可通過胎盤⑧Aportionofantibodycantransittheplacenta:豚鼠和兔子抗體可通過胎盤傳遞給胎兒；Theantibodyofcaviaprocellusandrabbitcantransittheplacentaintofetus.家畜只能通過初乳被動(dòng)免疫；Thelivestockcanonlytransittheantibodythroughforemilk.狗、貓、大鼠、小鼠通過胎盤接受少量，大部分則來自于初乳。Thedog,cat,rat,mousecanonlyacceptalittleantibodythroughplacenta,mostofantibodycomefromforemilk.抗體能否通過胎盤與Ig分子量的大小密切相關(guān)。WhethertheantibodycantransittheplacentadependsonthemolecularweightofIg.2．內(nèi)分泌作用2.Thefunctionofendocrine胎盤為一暫時(shí)性的內(nèi)分泌器官，能分泌雌二醇、孕酮（馬、羊）、PMSG、HCG（人）、PRL等。Placentaisatemporalendocrinalorganwhichcansecreteestradiol,progesterone(thehorseandsheep),PMSG,HCG(human),PRLandsoon.3．酶促、酶解作用3.Thecatalysisandzymolysisoftheplacenta

參與胎盤的代謝作用，大體可分為：氧化還原酶、轉(zhuǎn)移酶、水解酶、溶解酶、異構(gòu)化酶五類。Theoxido-reductase,transferase,hydrolase,cytaseandallomeraseparticipateinthemetabolismofplacenta.作用：分解物質(zhì)、合成物質(zhì)、輸送物質(zhì)、合成激素。Function:Composeanddecomposethesubstance,transportmaterial,synthetizehormone.四、臍帶

Part4.Umbilicalcord臍帶是連接胎兒和胎盤的紐帶，其外膜為羊膜，形成羊膜鞘，內(nèi)含：臍血管、臍尿管、卵黃囊遺跡等。Theumbilicalcordistheligamentthatconnectthefetusandplacenta,thetunicaexternaisamnioticmembrane,whichformtheamnioticsheath.Thereareumbilicalvessels,urachusandtheremainsoftheyolksacinumbilicalcord.長(zhǎng)度：牛：30－40cm羊：7-12cm豬：20-25cmLength:Bovine:30to40cmSheep:7to12cmSwine:20to12cm血管：Vessel:牛、羊：動(dòng)脈兩條,靜脈兩條，但進(jìn)入臍孔后合并為一條。Thecattleandsheep:Theyhavetwoarteriesandtwoveins,buttwoarteriesandtwoveinsconnectedintooneafterenteringthenavel.馬、豬：動(dòng)脈兩條，靜脈一條Thehorseandswine:havetwoarteriesandonevein.注：牛羊臍孔組織與血管之間聯(lián)系疏松，故生下后，臍帶不能撕太短，否則，易縮至腹腔，造成內(nèi)出血.Notes:Youcan’tteartheumbilicalcordtwoshortwhenthefetusarebornbecausethenaveltissuehaslooseconnectionwithvessel,orelseitwillretractintoenterocoelia,whichwillcauseinternalhemorrhage.五、牛多胎囊關(guān)系

Part5.Thereasonofmultiplefoetalsac牛：懷雙胎時(shí)，絕大多數(shù)是二胎囊接觸端上的尿膜絨毛膜合起來，血管吻合，故：Cow:Whenthecowarebigeminalpregnancy,mainlythecontactjawoftwofoetalsacsfilmthechorioallantois,thevascularanastomosis.So:異卵雙胎：如果雙胎性別不同，雌牛犢則無生生殖能力（90－95％）。公犢雖發(fā)育正常，亦不能種用。原因：雄胎睪丸發(fā)育早，雄激素抑制雌胎卵巢發(fā)育。Dizygotictwins:

90－95％offemalcalfaresterileifthetwinsaredifferenceingender.Thebullcalfarealsosterilethoughtheyarezoonal.Becausethetesticleofthebullcalfdevelopearly,itcansecreteandrogentosuppressthedevelopmentofthefemalcalf.同卵雙胎：一個(gè)受精卵，在發(fā)育過程中，形成兩個(gè)內(nèi)細(xì)胞團(tuán)，各自發(fā)育成完整個(gè)體。Identicaltwins:Inthedevelopment,oneoospermdevelopintotwoinnercellmass.Thattwoinnercellmassgrowintotwozooid.第五節(jié)懷孕時(shí)母體的變化

LessonFiveChangesinthematrixduringpregnancy可以作為懷孕診斷參考，加強(qiáng)飼養(yǎng)管理的依據(jù)。Changesinthematrixduringpregnancycanbeusedasdiagnosticreferenceofpregnancyandstrengthenthebasisoffeedingandmanagement.一、生殖器官的變化

PartOne.

Changesinreproductiveorgans1．卵巢：1.Ovarian:形成黃體：一是發(fā)生懷孕，黃體便持續(xù)下去，直到分娩（或流產(chǎn)）前幾天。即為妊娠黃體。Theformationofthecorpusluteum:Whenpregnancy,thecorpusluteumwillcontinuetobecorpusluteumverumuntilthebirth(orabortion)afewdaysago.

黃體往往比卵泡大，使卵巢體積增大。Usually,thecorpusluteumislargerthanfollicle,whichwillincreasethevolumeoftheovarian.2．子宮

2.Theuterus體積：增大首先是由孕角的子宮體開始，以后胎膜伸入空角，故“空角”實(shí)不空。但孕角的增大總要比空角大得多，兩者始終不對(duì)稱（多胎動(dòng)物例外）。Volume:Theincreasestartedfromtheuterusofpregnanthorn,afterthat,theembryolemmainsertintothecorner.Sothe“emptyhorn"isreallynotempty.Theyareasymmetric,becausetotalincreaseofpregnanthornismuchgreaterthantheemptyhorn(exceptmultiparousanimal).在懷孕前半期――由于胎兒尚小，主要是子宮肌纖維肥大、增長(zhǎng)，使子宮壁增厚。Inthefirsthalfofpregnancy,sincethefetusisstillsmall,thethickoftheuterinewallaremainlydepondedonthehypertrophyandincreaseofuterinemusclefiber.在懷孕后半期――由于胎兒迅速增大，使子宮壁擴(kuò)張，故子宮壁變薄。羊尤為明顯，故羊懷孕時(shí)子宮破裂病例較多。Inthelatterhalfofpregnancy,theuterinewallbecomesthinnerbecausetheuterinewallexpansionwiththerapidlyincreaseofthefetus.Especiallysheep,therearemorecasesoftheuterineruptureduringpregnancy.3．血管

3.vessel懷孕后，由于供應(yīng)子宮的血流量增加，故血管加粗，主要表現(xiàn)子宮中動(dòng)脈、子宮后動(dòng)脈。出現(xiàn)明顯懷孕脈搏。Afterpregnant,thevessel(mailythemid-uterinearteryandarterybehindtheuterine)willbecoarsenbecausethesupplyofbloodtouterinewillincrease.Thepregnancypulsewillappearclearly.牛的懷孕脈搏在5個(gè)月時(shí)就很明顯，這對(duì)診斷死胎有重要價(jià)值。Thepregnantpulseofthecowisclearinfivemonths,itisvaluableforthediagnosisofstillbirth.二、全身變化

PartTwo.Systemicchange初期：新陳代謝變得旺盛，食欲增加，消化力增加，體膘變好。initialstage:

metabolicbecomestrong,foodappetite,digestionandweightincrease.后期：胎兒發(fā)育快，牛胎兒體重的60％是在最后二個(gè)月生長(zhǎng)的。這時(shí)母畜營養(yǎng)的攝入不能滿足迅速發(fā)育的胎兒的需要，盡管食欲仍很好，或更旺盛，但變得消瘦。Laterstage:Thefetusgrowrapidly,60%weightofthebovinefetalgrowinthelasttwomonth.Atthistime,thenutritionalintakeofmatrixcannotmeettherapiddevelopingoffetus.Thus,thematrixbecomethininspiteofgoodappetiteorevenmore.1．礦物質(zhì)代謝――主要鈣、磷逆滲透梯度通過胎盤，胎兒需求量大，因此，如果補(bǔ)充不足，容易引起孕畜截癱。1.Mineralmetabolism:

Calciumandphosphorus,whichareneededtofetus,throughtheplacentainreverseosmosisgradient.Ifinsufficent,itiseasytocausetheparaplegiaofthematrix.2．心血管系統(tǒng)―心臟負(fù)擔(dān)增加出現(xiàn)心理性肥大，尤其左心室。懷孕后期，由于巨大子宮壓迫腹部及后肢靜脈，所以出現(xiàn)腹下、乳房、后肢的水腫。2.Cardiovascularsystem:Theincreasedburdenofthecardiacleadtopsychologicalhypertrophy,especiallytheventriculussinister.Inlatepregnancy,thematrixappeartohavetheoedemainhypogastric,breast,hindlimbwhichbecausethebellyandhindlimbveinsufferedthegreatpressurefromtheuterus.3．大小便變化――子宮增大，胃腸容積減少，排糞、排尿次數(shù)增加，數(shù)量減少。3.Changesinurine:

Hysterauxesis,thevolumeofthestomachandintestinedecrease.Thefrequencyofthedefecationandurinationincreased,butthequantitydecrease.4．呼吸變化――橫膈膜受到壓迫，腹壓增大，由腹式呼吸變?yōu)樾厥胶粑?.Changesinbreathing:Thediaphragmwasoppressed,abdominalpressureincrease,itchangesfromabdominalrespirationtothoracicrespiration.5．行為變化――穩(wěn)重、謹(jǐn)慎、容易疲勞、出汗。5.Changesinbehavior:Steady,cautious,exhausteasilly,perspiration.三、妊娠診斷

PartThree.Cyesiognosis（一）臨床診斷法SectionOne.Clinicaldiagnostics1.問診：1.Inquiry:配種次數(shù)、最后一次配后是否返情、配后一定時(shí)期母畜食欲是否改善。numberofserviceperconception,whetheritreturntooestrusafterthelasttimeofconception.Whetherthefoodappetiteofthematriximproveaftertheconception.2.視診：2.Inspection（1）外表觀察:腹部不對(duì)稱，馬多為左側(cè)，牛羊多為右側(cè)，豬部下垂。

(1)Exteriorinspection:Theabdomenisdissymmetric,usually,theleftsideofthehorseisdissymmetric,flocksandherdsisrightside,swineisbottom.（2）陰道視診:檢查陰道粘膜色澤、粘液性狀和子宮頸形狀及其粘液的變化。如馬未孕時(shí)陰道粘膜為淡粉紅色，懷孕3個(gè)月變?yōu)樯n白。羊當(dāng)剛打開陰道時(shí)粘膜為白色并迅速變?yōu)榧t色者，為懷孕癥狀。(2)Vaginalexamination:Includingthecolorofthevaginamucosa,thecharacterandthechangesofthemucusandtheshapeofcervix.Whenthehorsearenotpregnant,thevaginamucosaispink,butitwillbepaleafterpregnantforthreemonth.Thepregnancysymptomsofthesheepisthatthecolorofthevaginachangefromwhitetopinkwhenitisopen.3.外部觸診：3.Externalpalpation:馬：用手掌連續(xù)推動(dòng)左（右）腹壁最突出的地方、乳房稍前部。懷孕8-9月以后，可以感到腹腔內(nèi)有硬塊（胎兒）。Thehorse:Withtheleft(right)palm,keeppushingthemostprominentplaceoftheabdomen,alittlefrontfromthebreast,youcanfeelthatthereisalump(fetus)inenterocoeliawhenthehorsearepregnantfor8to9month.牛：用彎曲的手指節(jié)或拳觸診右側(cè)膝皺褶的前方，懷孕7-8月以上能觸到胎兒。The

cow:Palpatingthefrontoftheceaseofthe