---

- Discussion:
    - first major branch of the brachial artery is the profunda brachii;
    - arises from the brachial artery high in the arm, about level w/ lower edge of the latissimus dorsi tendon (18-25 cm above the medial 
           epicondyle);
    - leaves brachial artery to pass posteriorly company w/ radial nerve ;
    - it runs along the spiral groove of the humerus;
    - throughout its course, profunda artery & its paired venae comitantes lie close to the radial nerve;
    - profunda vessels are overlaid by two heads of triceps (long & lateral head);
           - emerging from beneath lateral head of the triceps, vessels enter lateral intermuscular septum;
    - w/ proximal and posterior approach the triceps muscle is split between its lateral and long heads to expose the entire length of profunda 
           brachii vessels in the spiral groove;
    - lateral intermuscular septum, which runs from deltoid insertion to lateral humeral epicondyle, is formed by investing fasciae of triceps
            posteriorly and brachialis & brachioradialis anteriorly;
           - distal continuation of the profunda artery, the posterior radial collateral artery, runs within septum and gives off cutaneous branches 
                  throughout its length