After completion of skin and cutaneous muscle removal the facial muscles will become visible. These can be broken down into muscles of facial expression or muscles of mastication. By breaking muscles into these two groups will also help in learning their motor innervation. The facial nerve innervates all of the muscles of facial expression, while the mandibular branch of the trigeminal innervates all but one of the muscles of mastication. At this time it is also important to note that the facial nerve DOES NOT provide sensory innervation to the face, this is supplied by branches from the trigeminal.

Additional groups of muscles associated with the head include: muscles of the larynx, muscles of the pharynx, muscles of the tongue, and muscles associated with the eye. Just as noted above, this type of grouping will also help in learning motor innervation. Muscles of the larynx are innervated by the vagus (CNX), muscles of the pharynx by the vagus and glossopharyngeal, muscles of the tongue by the hypoglossal, and the muscles that move the eye; occulomotor, trochlear, and abducents.

Study tip: List all of the muscles associated with each of these 6 groups of muscles. Note for the purposes of this course we will not dissect the muscles of the eye or the muscles associated with movement of the ear.