Which nerve is responsible for innervating the triceps brachii?

The triceps brachii, the muscle primarily responsible for extending the elbow joint, is innervated by the radial nerve. This nerve originates from the posterior cord of the brachial plexus and specifically targets muscle fibers of the triceps, stimulating them to contract and thus facilitating elbow extension.

The radial nerve travels down the arm and branches off to various muscles, with its main function being to control movements in the posterior compartment of the arm and forearm. Its innervation of the triceps brachii is essential for actions such as pushing and throwing, where elbow extension is crucial.

Understanding this neural pathway is important, especially in clinical contexts, as injury to the radial nerve can result in weakness or paralysis of the triceps, affecting overall arm functionality. This highlights the significance of recognizing which nerve is responsible for specific muscle innervation in anatomy and physiotherapy.