陆栖无脊椎动物的一种呼吸系统，由开口于体壁的气门和一系列气管组成.有爪动物门的栉蚕，气门很多，排列不规则而且无开闭机构，气管通常不分支，直接分布到各器官.蛛形纲的气门一般在附肢基节的后方.蜘蛛体内的气管有２类，有的气管密集成束伸入血腔中，交换气体后，氧由血液输送，称气管肺；另一类气管分支入组织中，直接进行气体交换.昆虫纲的气管系统最发达而完善.气门开口于体节两侧，大部分昆虫的气门之内为体壁下陷形成的气门腔，气门腔的外口有特殊构造可以开闭，控制空气的出入和防止水分散发或异物进入.气门腔的内口连接气管.气管也由体壁陷入而成，有相当固定的排列方式.大型气管为主干，纵行于血腔内背侧、腹侧和两侧.主干之间有横行气管相联系.空气由气门入主干沿分支的小气管至微气管进入组织或细胞内，在此直接行气体交换.气管内面有表皮形成的螺旋丝，富有弹性，使气管保持开张状态.有些昆虫的气管局部膨大为气囊，囊壁薄而无螺旋丝，具有促进气管内的通风作用及增加身体在水中和空气中浮力的作用.GOOGLE英文翻译:Terrestrial invertebrates as a respiratory system, by opening the valve on the body wall and a series of tracheal form. Onychophora Peripatus door, valve a lot of irregular arrangement and without opening and closing agencies, the trachea usually do not branch, Direct distribution to various organs. Arachnida of the valve is generally attached to the base section of the rear limbs. tracheal spiders have two body types, some tracheal intensive stretching from the blood into the beam cavity, the exchange of gases, the oxygen from the blood circulation, saying that tracheal lung; another branch of the trachea into the organization, the direct gas exchange. Insecta of the tracheal system, the most developed and complete. valve openings in Corpus Christi on both sides, most of the insects within the valve body wall subsidence of the formation of valve chamber , valve chamber outside the mouth closed can be opened with special structure, control access and prevent air or foreign matter into the water distribution. valve within the cavity of the mouth to connect the trachea. tracheal also made by the body wall into, there is relatively stable arrangement. Large the trachea as the backbone and dorsal longitudinal cavity in the blood, ventral, and side. backbone linking between the transverse trachea. the air from the valve into the trunk along a small branch of the trachea into the trachea to the micro-organizations or cells, in this direct OK gas exchange. tracheal epidermis to form inside a spiral wire, elastic, so that the opening of the trachea to maintain the state. Some of the insect tracheal partial enlargement of airbags, a thin cyst wall without helical wire, with the promotion of the role of endotracheal ventilation and increase the body water and air in the buoyancy effect.