has_quality has quality has quality tubular tube epithelium epithelial tube Epithelial tubes transport gases, liquids and cells from one site to another and form the basic structure of many organs and tissues, with tube shape and organization varying from the single-celled excretory organ in Caenorhabditis elegans to the branching trees of the mammalian kidney and insect tracheal system. AEO:0000114 epithelial or endothelial tube uberon contrast with a multi-tissue tube, which has as parts both epithelium, connective tissue, possibly muscle layers FBbt:00007474 UBERON:0003914 EHDAA2:0003114