Deep artery of arm
It descends in the arm before ending by anastomosing with the radial recurrent artery.[citation needed] It follows closely the radial nerve, running at first backward between the long and medial[1] heads of the triceps brachii, then along the groove for the radial nerve (the radial sulcus), where it is covered by the lateral head of the triceps brachii, to the lateral side of the arm; there it pierces the lateral intermuscular septum, and, descending between the brachioradialis and the brachialis to the front of the lateral epicondyle of the humerus, ends by anastomosing with the radial recurrent artery.It gives branches to the deltoid muscle (which, however, primarily is supplied by the posterior circumflex humeral artery) and to the muscles between which it lies; it supplies an occasional nutrient artery which enters the humerus behind the deltoid tuberosity.A branch ascends between the long and lateral heads of the triceps brachii to anastomose with the posterior humeral circumflex artery; the medial collateral artery, a branch, descends in the middle head of the triceps brachii and assists in forming the anastomosis above the olecranon of the ulna; and, lastly, a radial collateral artery runs down behind the lateral intermuscular septum to the back of the lateral epicondyle of the humerus, where it anastomoses with the interosseous recurrent and the inferior ulnar collateral arteries.This article incorporates text in the public domain from page 591 of the 20th edition of Gray's Anatomy (1918)