Which plexuses innervate the scalene muscles?

The scalene muscles, which are located in the lateral region of the neck, primarily receive their innervation from the cervical plexus and the brachial plexus. The cervical plexus supplies the scalene muscles through its branches, particularly the ventral rami of the lower cervical nerves (C5-C8), which play a crucial role in motor control. Meanwhile, the brachial plexus also contributes to the innervation of the scalene muscles, particularly through the roots and trunks that pass between the scalene muscles.

This combination of innervation reflects the anatomical relationship and functional relevance of these structures in neck and upper limb movement. The cervical plexus primarily provides nerves that facilitate cervical muscle function and sensation, while the brachial plexus enters the upper limb and innervates muscles involved in arm and shoulder movements, reflecting the overlap in their roles as they relate to the scalene muscles.