Anatomy of the Cervical Plexus and Its Branches

The cervical plexus is a neurological structure of great interest within the head and neck region. It consists of contributions from the ventral rami of the first four cervical spinal nerves. With the exception of the first cervical nerve, these rami divide into ascending and descending branches to form intricate loops that innervate the muscles of the head and neck along with providing sensory supply. Along with the interactions between the contributing ventral rami forming the cervical plexus, the branches also yield contributions from the cranial nerves. An assortment of branches arises from the cervical plexus and includes the ansa cervicalis, lesser occipital, greater auricular, supraclavicular, transverse cervical, and phrenic nerves. Their anatomy, and possible variants, are discussed within this chapter.