Deep brachial artery

Origin and course

The deep brachial artery originates from the posteromedial side of the brachial artery at the level of the lower margin of the long head of triceps brachii. It courses posteriorly, passing through the triangular interval of the arm, between the long and medial heads of triceps. The artery then curves around the posterior surface of humerus and emerges into the posterior compartment of the arm.

Along its course, the deep brachial artery follows the radial nerve. Together with the nerve, it traverses the radial groove of humerus in the posterior arm, where it is covered by the long head of triceps brachii. Under the long head of triceps, the artery splits into its two terminal branches; radial collateral and middle collateral arteries.

Branches and supply

Just prior to its terminal bifurcation, the deep brachial artery gives off a number of branches including an ascending deltoid branch that anastomoses with the branches of the posterior circumflex humeral artery and supplies the deltoid muscle, as well as muscular collateral branches for the lateral and medial heads of the triceps brachii muscle

The deep brachial artery ends by bifurcating into two branches;

• The radial collateral (anterior descending) artery follows the radial nerve and enters the lateral intermuscular septum of the arm. Via this route, it emerges on the anterior side of the lateral humeral epicondyle, directly between the brachialis and brachioradialis muscles. It gives off muscular branches to supply these two muscles, after which it terminates by anastomosing with the radial recurrent branch of the radial artery. Via this anastomosis, it is included into the arterial supply of the elbow. Along its course through the lateral intermuscular septum, the radial collateral artery gives off small branches to supply the radial nerve, as well as perforating branches to supply the septum itself and the overlying skin.
• The middle collateral (posterior descending) artery passes medially and then descends along the lateral intermuscular septum to reach the elbow. It courses over the long head of triceps brachii, being covered with brachialis in its proximal part and with the brachioradialis muscle in its distal part. Along its course, it gives off several perforating branches that supply the surrounding fascia and overlying skin, as well as a small muscular branch for the anconeus muscle. The middle collateral artery terminates posterior to the lateral condyle of humerus by anastomosing with the interosseous recurrent artery, a branch of the ulnar artery. Via this anastomosis, this artery also participates in the arterial network of the elbow.

Anatomical variations

The origin of the deep brachial artery can vary; the artery may arise via a common origin with the posterior circumflex humeral artery, or directly from the axillary artery.