小血管 上皮 固有层 粘膜肌层 2食管腺 ,粘膜下层 环行肌 一纵行肌 3 muscularis 外膜 g inner circular and outer longitudinal e upper 1/3: skeletal muscle e middle 1/3: mixed of skeletal m and smooth muscle e lower 1 /3: smooth muscle adventitia: fibrosa3) muscularis: inner circular and outer longitudinal upper 1/3: skeletal muscle middle 1/3: mixed of skeletal M and smooth muscle lower 1/3: smooth muscle 4) adventitia: fibrosa