develops from ends during starts during dorsal aorta intersomitic vessel intersomitic artery lab The small branching sprouts of the dorsal aorta that grow across the medial surface of the somite, turn right angles to grow over that surface and then fuse with other sprouts and form the vertebral arteries adjacent to the neural tube; the intersomitic arteries supply the body wall and persist in the adult as the posterior intercostal, subcostal and the lumbar arteries. 2011-08-30T02:29:23Z XAO:0004165 xenopus_anatomy UBERON:0006001 NF stage 37 and 38 NF stage 47