Figure 5: (a) Embryonic arteries-as per Baeza's modification of Singer's staging. a -Primitive axial artery. c, d, and m-Radial, ulnar, and median branches, respectively. b-Superficial brachial artery. k + j-Lateral branch of superfi cial brachial artery. g + h-Medial branch of superficial brachial artery. f-Median branch of superficial brachial artery. l, n, e, i-Anastomotic channels between superfi cial and primitive axial system. (b) Normal development. b, k, f, i, g, l, n, e-Segments regress. a-Deep brachial artery. d + h-Ulnar artery. c + j-Radial artery. m-Common interosseous artery