part of part of in taxon Homo sapiens caudal vertebra dorsal region element hemal arch haemal arch Bony canal attached to the ventral surface or the vertebral centrum that encloses and protects the caudal artery and vein ventrally. The arch consists of right and left halves, which are fused ventrally to give a V- or Y-shape to the ventral aspect of the vertebra.[AAO] ventral arch TAO:0000519 A vertebral arch that is attached to the ventral surface or the vertebral centrum and encloses and protects the caudal artery and vein ventrally. Hemal arches extend ventrally from the centra of caudal and transitional vertebrae to enclose the caudal artery and vein. In cyprinids, the hemal arch forms directly in membrane bone.[TAO] ZFA:0000519 AAO:0000726 chevron ventral arcocentrum relationship loss: develops_from basiventral (TAO:0001361)[TAO] In cyprinids, the hemal arch forms directly in membrane bone[ZFA] Wikipedia:Haemal_arch UBERON:0006065 fish, most reptiles, some birds, and some mammals with long tails. arch of centrum of vertebra