Proprioceptors in Cephalic Muscles

Abstract

The proprioception from the head is mainly mediated via the trigeminal nerve and originates from special sensitive receptors located within muscles called proprioceptors. Only muscles innervated by the trigeminal nerve, and rarely some muscles supplied by the facial nerve, contain typical proprioceptors, i.e. muscle spindles. In the other cephalic muscles (at the exception of the extrinsic muscles of the eye) the muscle spindles are replaced by sensory nerve formations (of different morphologies and in different densities) and isolated nerve fibers expressing mechanproteins (especially PIEZO2) related to proprioception. This chapter examines the cephalic proprioceptors corresponding to the territories of the trigeminal, facial, glossopharyngeal and hypoglossal nerves.