Posterior circumflex humeral artery

At a glance

English

Posterior circumflex humeral artery

Latin (TA2)

Arteria circumflexa posterior humeri

System

Artery

Region

Upper limb

Side

Paired, left and right

About the posterior circumflex humeral artery

The posterior circumflex humeral artery is one of the last branches of the axillary artery. It leaves the third part of that vessel, beyond pectoralis minor, close to the lower edge of subscapularis and often in common with or just beside the much smaller anterior circumflex humeral artery. It is noticeably the larger of the two circumflex arteries.

From its origin it turns backwards together with the axillary nerve, and the two pass through the quadrangular space. This gap is bounded above by teres minor (and subscapularis in front), below by teres major, medially by the long head of triceps and laterally by the humeral surgical neck. Emerging behind, the artery and nerve wind round the surgical neck from back to front, lying under cover of deltoid.

The artery is the main supply of deltoid, and it also sends branches to teres major, teres minor and the long head of triceps, and to the shoulder joint. Around the neck of the humerus it joins the anterior circumflex humeral artery to form an arterial ring. A descending branch meets the deltoid branch of the deep artery of the arm, and other twigs link with the acromial branches of the thoracoacromial and suprascapular arteries over the shoulder.

Its close partnership with the axillary nerve explains its clinical importance. Fractures of the humeral surgical neck and dislocations of the shoulder can stretch or tear both structures, so after such injuries the sensation over the lower deltoid and the strength of the muscle are tested. Compression of the artery and nerve in the quadrangular space, sometimes seen in throwing athletes, causes pain at the back of the shoulder and can lead to clots in the vessel. The artery also contributes much of the blood supply to the head of the humerus.

Course and supply

Arises from

The third part of the axillary artery, near the lower border of subscapularis.

Ends in

Winds round the humeral surgical neck and ends in deltoid, anastomosing with the anterior circumflex humeral artery and the deep artery of the arm.

Supplies

Supplies deltoid, teres major, teres minor, the long head of triceps and the shoulder joint, and helps supply the head of the humerus.