The facial seventh cranial nerve arises from the pontomedullary junction by two roots: 1 the motor root conveying fibers to muscles derived from second branchial arch mesoderm and 2 the nervus intermedius conveying visceral sensory fibers from the tongue and palate, and preganglionic parasympathetic fibers to the pterygopalatine and submandibular ganglia. The roots pass into the internal acoustic meatus where they join. At the lateral end of the meatus, the facial nerve passes into the facial canal. The nerve then turns sharply posteriorly at the geniculum. The geniculate sensory ganglion is situated here, and the greater petrosal nerve to the pterygopalatine ganglion arises from this region.
5g. The Facial Nerve
NCBI Bookshelf. Dominika Dulak ; Imama A. Authors Dominika Dulak 1 ; Imama A. Naqvi 2. It arises from the brain stem and extends posteriorly to the abducens nerve and anteriorly to the vestibulocochlear nerve. It courses through the facial canal in the temporal bone and exits through the stylomastoid foramen after which it divides into terminal branches at the posterior edge of the parotid gland.
In this article, we shall look at the anatomical course of the nerve, and the motor, sensory and parasympathetic functions of its terminal branches. 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. It begins as two roots; a large motor root , and a small sensory root the part of the facial nerve that arises from the sensory root is sometimes known as the intermediate nerve.
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. It arises from the brainstem from an area posterior to the cranial nerve VI abducens nerve and anterior to cranial nerve VIII vestibulocochlear nerve. 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. Distal to stylomastoid foramen , the following nerves branch off the facial nerve:. Intra operatively the facial nerve is recognized at 3 constant landmarks: [ citation needed ]. The cell bodies for the facial nerve are grouped in anatomical areas called nuclei or ganglia.