贝壳状结构任一种类似于贝壳的形状结构,例如人的外耳
Any of various structures, such as the external ear, that resemble a shell in shape.
(先天性)闭锁,无孔正常的身体孔或管道,如肛门、肠或外耳道的缺失或闭合
The absence or closure of a normal body orifice or tubular passage such as the anus, intestine, or external ear canal.