胃肠道正常组织学
NormalHistologyofGastrointestinalTract
食管（Esophagus）
解剖学（Anatomy）
Theesophagusisahollowmusculartubethatconnectsthepharynxtothestomach.Itbeginsintheneckregionatthecricoidcartilage,traversesthroughthethoraxintheposteriormediastinum,andextendspastthediaphragmuptothestomach.Inanadult,itmeasuresapproximately25cminlength.Atendoscopy,usuallythelengthoftheesophagusismeasuredastheanatomicdistancefromtheincisorteeth.Thiscorrespondstotheesophagusbeginningat15–18cmfromtheincisorteethandextendingtothegastroesophagealjunction(GEJ)whichislocatedatapproximately40cm.Theadulthumanesophaguscanbedividedintocervical,thoracic,andabdominalparts.
食管是一个连接咽和胃的中空肌性管腔。它开始于环状软骨处的颈部，穿过后纵隔的胸部，并从横膈膜一直延伸到胃。在成年人，它的长度约为25厘米。在内窥镜检查中，食道的长度通常是以离切牙的解剖距离来测量的。这对应于从切牙的15～18厘米开始的食管，并延伸到位于约40厘米处的胃食管交界处（GEJ）。成人食管可分为颈部、胸部和腹部。
Theupperesophagealsphincterisusuallyreferredtoasa3cmsegmentoftheproximalesophagusatthelevelofthecricopharyngeusmuscle.Theloweresophagealsphincterisusuallyreferredtoasa2–4cmsegmentjustproximaltotheanatomicGEJ,atthelevelofthediaphragm.Ofnote,therearenowell-establishedanatomiclandmarksthatoutlinethesesphinctersinrelationtotheesophagealmusculature,thoughtheymayberecognizedduringendoscopy.
食管上段括约肌通常被称为食管近端3cm段，位于环咽肌水平。食管下段括约肌通常仅位于解剖部位GEJ近端2～4厘米部分，位于膈肌水平。值得注意的是，虽然这些括约肌可以在内镜下被识别出来，但并没有明确的解剖学标志来勾勒出这些括约肌与食管肌肉的关系。
Thenormalesophagushasseveralpointsofconstrictionalongitscourse.Theyareatthecricoidoriginoftheesophagus,attheaorticarch,atthecrossingoftheleftmainbronchusandleftatrium,andatthepassagethroughthediaphragm.Theseconstrictionsareclinicallyrelevantasfoodormedicationpillscanbe
