Question #400

Biceps brachii has two heads, the long head arises from the supraglenoid tubercle of the scapula, the short head arises from the coracoid process.

It also has two sites of insertion. The biceps tendon inserts into the radial tuberosity on the medial aspect of the radius while a wide flat bicipital aponeurosis extends over the cubital fossa to insert into the subcutaneous border of the ulna.

Due to the insertion into the radial tuberosity, on contraction biceps first supinates then forearm then flexes the elbow. In pronation biceps brachii is therefore only a weak flexor of the elbow joint.

It lies lateral to coracobrachialis and superficial to brachialis.

It is supplied by the musculocutaneous nerve which, after piercing coracobrachialis, lies between biceps and brachialis.

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