Scapular anastomosis

The transverse cervical artery from the subclavian, usually the first part, occasionally the third part, has a descending branch (the dorsal scapular artery) which accompanies the dorsal scapular nerve. It runs down the vertebral border of the scapula to its inferior angle. The suprascapular artery from the sub­clavian, usually the first part (thyrocervical trunk in common with the transverse cervical) but occasionally the third part, crosses over the transverse ligament of the scapular notch, passes through the supraspinous fossa, turns around the lateral border of the spine of the scapula and supplies the infraspinous fossa as far as the inferior angle. The subscapular artery, branching from the third part of the axillary, supplies the subscapularis muscle in the subscapular fossa as far as the inferior angle. Its circumflex scapular branch enters the infra­spinous fossa on the dorsal surface of the bone. All the vessels anastomose, thus connecting the first part of the subclavian with the third part of the axillary artery. The companion veins form corresponding anastomoses.