human_reference_atlas Homo sapiens capillary http://upload.wikimedia.org/wikipedia/commons/2/2f/A_red_blood_cell_in_a_capillary,_pancreatic_tissue_-_TEM.jpg vasculature NLXANAT:090902 https://github.com/obophenotype/uberon/issues/2186 capillary vessel Any of the smallest blood vessels connecting arterioles with venules. capillary capillaries lack tunica media and tunica adventitia; only the endothelial wall of the tunica intima belongs MA:0000065 ZFA:0005250 TAO:0005250 Wikipedia:Capillary CALOHA:TS-2006 EFO:0001906 VHOG:0001253 The appearance of Chordata and subsequently the vertebrates is accompanied by a rapid structural diversification of this primitive linear heart: looping, unidirectional circulation, an enclosed vasculature, and the conduction system.[well established][VHOG] AS UBERON:0001982 MESH:D002196 FMA:63194 AAO:0010252 EV:0100035 blood capillary NCIT:C12685 capillary vasculature BTO:0002045 UMLS:C0935624 not all sources agree capillary is a blood vessel - consider adopting EMAPA superclass of vascular element XAO:0000116 uberon EMAPA:35198 Any of the tiny blood vessels connecting the arterioles to the venules.[AAO] right cardiac atrium left cardiac atrium heart right ventricle heart left ventricle interventricular septum blood microvessel