Musculocutaneous nerve

Giving a twig to the shoulder joint and a branch to coracobrachialis the nerve proceeds between the two conjoined parts of coracobrachialis, and comes to lie between biceps and brachialis, accompanied by many branches of the brachial artery and tributaries of the brachial veins. While lying in this intermuscular plane it supplies both muscles. Its remaining fibres, purely cutaneous now, appear at the lateral margin of the biceps tendon as the lateral cutaneous nerve of the forearm. The musculocutaneous is the nerve of the flexor compartment of the arm, supplying all three muscles therein.