2-Minute Neuroscience: Facial Nerve (Cranial Nerve VII)
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- เผยแพร่เมื่อ 8 ก.ย. 2024
- The facial nerve (cranial nerve VII) has multiple functions, but is best known for its role in controlling the muscles of facial expression. In this video, I cover all of the functions of the facial nerve, as well as describe what can happen when the nerve is damaged.
TRANSCRIPT:
Welcome to 2 minute neuroscience, where I explain neuroscience topics in 2 minutes or less. In this installment I will discuss the facial nerve.
The facial nerve, also known as cranial nerve VII, is best known for its role in controlling the muscles of facial expression, as well as a number of other muscles of the face and head such as certain muscles involved with swallowing and jaw movement, muscles of the external ear, and the stapedius muscle, which is found in the middle ear and is involved with dampening loud noises. The facial nerve also receives sensory information from the outer ear and from the taste buds on the anterior two-thirds of the tongue, and it supplies most major glands in the head, including the lacrimal glands for tear production, the submandibular and sublingual salivary glands, and the mucous glands of the nose, paranasal sinuses, and palate.
The facial nerve is associated with several nuclei in the brainstem. The motor portion of the facial nerve originates in the facial motor nucleus in the pons. The portion of the nerve that supplies the glands mentioned previously originates from the superior salivatory nucleus in the pons. Taste information travels to the nucleus of the solitary tract in the medulla. And the sensory information from the outer ear travels to the spinal trigeminal nucleus in the medulla.
Facial nerve damage can cause a variety of symptoms, but the most recognizable of them is weakness and/or paralysis of the muscles of facial expression on the same side of the head that the damaged nerve supplies. The patient’s mouth on the affected side may droop, and he may be unable to close the eye on the affected side. In most cases of facial nerve palsy, the cause of the dysfunction is not known; when this is the case it is referred to as Bell’s palsy.
References:
Brackmann DE, Fetterman BL. Cranial Nerve VII: Facial Nerve. In Goetz CG, ed.
Textbook of Clinical Neurology, 3rd ed. Elsevier; 2007.
Sanders RD. The Trigeminal (V) and Facial (VII) Cranial Nerves. Head and Face Sensation and Movement. Psychiatry (Edgmont). 2010 Jan; 7(1): 13-16.
Wilson-Pauwels L, Akesson EJ, Stewart PA, Spacey SD. Cranial Nerves in Health and Disease. 2nd ed. London: BC Decker, Inc; 2002.