The profunda brachii artery also referred to as the deep brachial artery, is the first and largest branch of the brachial artery. It originates from the posterior portion of the brachial artery, just inferior to the lower border of the teres major muscle. It then traverses the triangular interval into the posterior compartment of the arm along with the radial nerve. Once in the posterior compartment, the profunda brachii artery gives off an arterial branch that anastomoses with the posterior circumflex humeral artery before continuing inferiorly along the radial sulcus (radial groove). Below the inferior border of the latissimus dorsi muscle, it branches into the radial collateral artery and middle collateral artery. The radial collateral artery further divides into the anterior radial collateral artery and the posterior radial collateral artery. The anterior radial collateral artery anastomoses with the radial recurrent artery while the middle collateral artery and posterior radial collateral artery both anastomose with the recurrent interosseous artery.