[名词解释] 节肢

血体腔 马氏管 胃型或肠型可见于（） ["急性胃扩张","幽门管溃疡","肠梗阻","极度消瘦者","Crohn病"] 异律分节 易与下移的正常肝脏下缘相混淆的情况有（） ["肝炎","肝脏肿瘤","盲肠癌","腹直肌腱划","横结肠肠管"] 节肢