ulnar veins ulnar veins in anatomy, the ulnar veins are venae comitantes for the ulnar artery. they mostly drain the medial aspect of the forearm. they arise in the hand and terminate when they join the radial veins to form the brachial veins. ulnar veinsveins of the upper limbdetailssourcesuperficial palmar venous archdrains tobrachial veinarteryulnar arteryidentifierslatinvena ulnaris (plural: venae ulnares)ta98a12.3.08.030ta24985fma70897anatomical terminology they follow the same course as the ulnar artery. additional images the deep veins of the upper extremity. ulnar veins ulnar vein