VASCULARIZATION OF THE HUMAN HUMERUS

The proximal third of the humerus is fed by the anterior and posterior circumflex arteries of the axillary artery. They construct a fine ana stomoses network at the humeral head as well as longitudinal anastomos es to the diaphysis. The middle third of the humerus is maintained by the rami musculoperiostales originating in both the brachial artery an d the deep brachial artery. These periosteal vessels are formed both h orizontally and vertically. The distal third of the humerus is mainly supplied by the horizontal anastomoses of the collateral arteries. The inner part of the bone is normally penetrated by just one nutrient ar tery entering the nutrient canal below the middle of the humerus.