Anatomical characters lung: alveoli is little; rich in blood vessle mediastina: big, tissue is rarefaction (纵隔) mediastina displacemen thoracic cage: short barrel chest ib horizonal Diaphragma horizonal anoxia Retention of co cvanosis 儿学2的的Anatomical characters lung: alveoli is little; rich in blood vessle mediastina: big, tissue is rarefaction （纵隔） thoracic cage: short barrel chest rib horizonal Diaphragma horizonal + mediastina displacemen anoxia Retention of co2 cyanosis