In this article, we shall look at the anatomy of the facial nerve — its anatomical course, functions and clinical correlations. The facial nerve is associated with the derivatives of the second pharyngeal arch :. The course of the facial nerve is very complex. There are many branches, which transmit a combination of sensory, motor and parasympathetic fibres. The nerve arises in the pons , an area of the brainstem.
Skip to main content. It is important to note that while the facial nerve branches within the parotid gland, it does not provide autonomic innervation to the gland This is supplied by the auriculotemporal division of V3. CN VII is often tested during physical examination and its function can be reported using the House-Brackmann Scale Hint: 1 is normal, 6 is completely non-functional. Parasympathetic Innervation: CN VII provides pre ganglionic parasympathetic innervation to: Submandibular glands Sublingual glands Lacrimal glands Mucous membranes of the nose, palate, and pharynx It is important to note that all of the post ganglionic parasympathetic nerve fibers from CN VII are actually carried to their ultimate targets via divisions of CN V. Parasympathetic innervation in the head and neck promotes the production of mucous, tears, and saliva and is counter regulated by sympathetic innervation. Anatomic Pathway of Parasympathetics: The parasympathetic fibers of CN VII originate in the superior salivary nucleus of the pons and leave the cerebellopontine angle as the nervus intermedius of Wrisberg.
The facial nerve is one of the key cranial nerves with a complex and broad range of functions. Although at first glance it is the motor nerve of facial expression which begins as a trunk and emerges from the parotid gland as five branches see facial nerve branches mnemonic , it has taste and parasympathetic fibers that relay in a complex manner. The facial nerve is the only cranial nerve that may show normal post-contrast enhancement, although this applies only to the labyrinthine segment up to the stylomastoid foramen.
It emerges from the pons of the brainstem , controls the muscles of facial expression , and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue. The facial nerve also supplies preganglionic parasympathetic fibers to several head and neck ganglia. The facial and intermediate nerves can be collectively referred to as the nervus intermediofacialis. The motor part of the facial nerve arises from the facial nerve nucleus in the pons , while the sensory and parasympathetic parts of the facial nerve arise from the intermediate nerve.