Question

The muscular branches of the radial nerve innervates the following muscles EXCEPT?

1) Long head of the biceps brachii
2) Medial head of the triceps brachii
3) Anconeus
4) Extensor carpi radialis brevis

Answer 1

The Long head of the biceps brachii is not innervated by the radial nerve; this muscle is innervated by the musculocutaneous nerve and is a flexor rather than an extensor of the forearm.

Step-by-step explanation:

The muscular branches of the radial nerve innervate several muscles in the arm, but of the options provided, the muscle that is not innervated by the radial nerve is the Long head of the biceps brachii. The radial nerve primarily innervates muscles in the posterior compartment of the arm and forearm, which are involved in extension. This includes muscles like the medial head of the triceps brachii, the anconeus, and the extensor carpi radialis brevis. The biceps brachii is actually innervated by the musculocutaneous nerve and is part of the anterior compartment of the arm, functioning as a flexor of the forearm.