Brachial region
The brachial region, in other words “the arm”, is the region of the upper extremity located proximal to the elbow joint. It is the origin and insertion of several muscles anteriorly and posteriorly, and also consists of several veins, arteries, and nerves.
Veins and Arteries:
- Most superficially, the cephalic vein runs laterally in the brachial region above the brachial fascia (deep fascia) and drains into the axillary vein.
- The basilic vein initially runs superficial to the brachial fascia medial to the biceps brachii, then above the medial epicondyle, it perforates the fascia and runs upwards to drain into the axillary vein.
- The brachial artery (continuation of the axillary artery) supplies the region. It becomes the brachial artery at the lower border of the teres major muscle. The brachial artery runs medially in the brachial region, and it gives off branches including the deep brachial artery “arteria profunda brachialis”. Then, the brachial artery goes laterally into the cubital fossa, where it bifurcates into the radial and ulnar arteries, which run in the forearm (antebrachium). The brachial vein runs with the brachial artery.
Muscles:
- The muscles in the anterior and posterior compartments of the arm are separated by the medial and lateral intermuscular septa.
- Anteriorly:
- Biceps Brachii muscle - origin (long head): supraglenoid tubercle of scapula, origin (short head): coracoid process of scapula; insertion: radial tuberosity and bicipital aponeurosis.
- Brachialis muscle - origin: anterior surface of the distal half of the shaft of humerus; insertion: ulnar tuberosity.
- Coracobrachialis muscle - origin: coracoid process of scapula; insertion: anteromedial surface of the humerus shaft.
- Posteriorly:
- Triceps barchii muscle - origin (long head): infraglenoid tubercle of scapula, origin (medial head): posterior surface of shaft of humerus inferior to radial groove, origin (lateral head): posterior surface of shaft of humerus superior to radial groove; insertion: olecranon of ulna.
Nerves:
- You should know the respective positions of the nerves in the transverse section and what they innervate.
