The ponticulus posterior of the atlas.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001270:Cervical Atlas / Q000002:abnormalities* / Q000000981:diagnostic imaging; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011859:Radiography