Figure 6
Schematic diagram of the development of the brachial artery (modified from Lippert & Pabst (Lippert & Pabst 1985 )). a: In embryos of body length 4–7 mm, the left and right 6th (or 7th) cervical intersegmental artery develops as the axillary artery, becoming the brachial artery and then the interosseous artery, until it reaches the capillary plexus as finger arteries. b: The median artery arises from the interosseous artery and becomes the main supply for the finger arteries, while the periphery of the interosseous artery atrophies. c: When body length reaches 18 mm, the ulnar artery branches off the brachial artery and makes an anastomosis with the distal region of the median artery, forming the carpal arch. d: At body length 21 mm, the SBA is generated and reaches the wrist. e, f: When body length reaches 23 mm, the median artery degenerates, and the periphery of the SBA makes an anastomosis with the superficial volar arch. At the elbow, the anastomotic branch between the brachial artery and the SBA broadens, while the proximal side of the SBA atrophies, and the distal side becomes the radial artery.