Cranial Nerve VII: Facial Nerve Motor function: muscles of facial expression. Parasympathetic function: innervation to lacrimal glands and some salivary gland. Visceral sensory function: taste from anterior 2/3 of tongue

Anatomical Course Intracranial – the course of the nerve through the cranial cavity, and the cranium itself. Extracranial – the course of the nerve outside the cranium, through the face and neck.

Intracranial branches

Extracranial branches

The Otic Parasympathetic Ganglia provides secretomotor innervation to the parotid gland The Glossopharyngeal nerve (IX) provides presynaptic fibers to this ganglion The glossopharyngeal nerves innervate the structures that make your tongue glossy (parotid glands, which are the largest salivary glands) Anatomically, the parotid glands are right next to the ear (hence, "otic" ganglia). -The Submandibular parasympathetic ganglia provide secretomotor innervation to the submandibular and sublingual glands -The Chorda Tympani branch of the Facial Nerve supplies the presynaptic fibers

Intracranial Lesions: occur during the intracranial course of the facial nerve   The muscles of facial expression will be paralysed or severely weakened.  The other symptoms produced depend on the location of the lesion, and the branches that are affected: Chorda tympani – reduced salivation and loss of taste on the ipsilateral 2/3 of the tongue. Nerve to stapedius – ipsilateral hyperacusis (hypersensitive to sound). Greater petrosal nerve –  ipsilateral reduced lacrimal fluid production. The most common cause of an intracranial lesion of the facial nerve is middle ear pathology – such as a tumor or infection. If no definitive cause can be found, the disease is termed Bell’s palsy.

Extracranial Lesions: occur during the extracranial course of the facial nerve (distal to the stylomastoid foramen) Only the motor function of the facial nerve is affected, resulting in paralysis or severe weakness of the muscles of facial expression. There are various causes of extracranial lesions of the facial nerve: Parotid gland pathology – e.g a tumor, parotitis, surgery. Infection of the nerve  – particularly by the herpes virus. Compression during forceps delivery of the baby. Idiopathic – If no definitive cause can be found, the disease is termed Bell’s palsy.

Bells-Palsy-Right-Side: weakness of the muscles of facial expression, due to facial nerve paralysis

The pharyngeal plexus is formed by: the pharyngeal and laryngeal branches of the vagus nerve [X]; The pharyngeal branches of the glossopharyngeal nerve [IX].

Online http://emedicine.medscape.com/article/1873373-overview#a2 https://quizlet.com/41588314/i-oral-cavity-and-pharynx-flash-cards/