The nature and location of lower esophageal ring.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001344:Autopsy; D002648:Child; D002675:Child, Preschool; D004848:Epithelium / Q000473:pathology; D004940:Esophageal Stenosis / Q000473:pathology; D004943:Esophagogastric Junction / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000473:pathology; D004947:Esophagus / Q000033:anatomy & histology / Q000473:pathology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000473:pathology; D009130:Muscle, Smooth / Q000473:pathology; D011859:Radiography; D012737:Sex Factors