GROSS ANATOMY

Detailed explanation-1: -The musculocutaneous nerve innervates the three muscles of the anterior compartment of the arm: the coracobrachialis, biceps brachii, and brachialis muscles.

Detailed explanation-2: -The musculocutaneous nerve is responsible for innervating the flexors of the arm, including the biceps brachii, coracobrachialis, and the medial aspect of the brachialis. The radial nerve innervates the triceps brachii, lateral aspect of the brachialis, anconeus, brachioradialis, and extensor carpi radialis longus.

Detailed explanation-3: -Along its course in the arm region, the radial nerve provides muscular branches that innervate the triceps brachii, anconeus, and brachioradialis muscles.

Detailed explanation-4: -The musculocutaneous nerve is derived from the lateral cord of the brachial plexus and innervates the biceps brachii, brachialis, and coracobrachialis muscles (C5–C6), terminating as the lateral cutaneous nerve of the forearm.

Detailed explanation-5: -It is innervated by the radial nerve, so is not affected by musculocutaneous nerve injury. Supination and flexion at the shoulder joint is also weakened but not lost due to role of supinator and pectoralis major respectively.