Cranial Nerve VII Case Study

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In this particular case study, cranial nerve VII, the facial nerve, is damaged. The patient has loss of taste, which is associated with the sensory nerves of the facial nerve (Walker,2017). The loss of taste, which is located on the anterior 2/3 of the tongue is the key to this conclusion, as the facial nerve controls the sense of taste on the anterior 2/3 of the tongue, as the case study states the cranial nerve is only partially functional (Walker,2017).
Cranial nerve VII, or the facial nerve is a mixed nerve which includes both sensory and motor nerve fibers (Walker). The facial nerve originates in the pons of the brainstem (Curry,2017). There is a sensory and motor root where the nerve originates from the pons (Curry,2017). As these two
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The facial nerve innervates the lacrimal gland by way of the greater petrosal nerve, which are parasympathetic nerve fibers (Curry,2017). Motor nerve fibers innervate the stapedius muscle within the middle ear (Curry,2017). Sensory nerve fibers then innervate the tongue for taste via the chorda tympani (Curry,2017) The chorda tympani also innervates the salivary glands in the sublingual and submandibular areas (Curry). Then, the facial nerve exits the cranium through the stylomastoid foramen (Curry,2017). The first branch of the facial nerve after it exits the cranium is the posterior auricular nerve. This nerve is a motor nerve that innervates the muscles around the ear, the stylohyoid muscle and the digastric muscle, as well (Curry,2017). The motor root of the facial nerve then goes through, but does not innervate the parotid gland (Curry,2017). Within the parotid gland, the facial nerve splits into the following branches, the temporal branch, the zygomatic branch, the buccal branch, the marginal mandibular branch, and …show more content…
One would also ask the patient to do a series of facial expressions such as: frown, show their teeth, puff out their cheeks (, 2017). While the patient is doing this the examiner would carefully watch for any asymmetry. The nasolabial grooves are also a great place to look for symmetry in muscle tone (, 2017). The examiner would also ask the patient to look up to wrinkle forehead (, 2017). The examiner would then feel the muscle to check for any asymmetry (, 2017). Asymmetry is really key to check the facial nerve. For a healthier nerve there would be symmetric movement of the face as well as symmetric muscle tone (, 2017). To check for taste, the examiner would put a small amount of sugar or salt on the tongue and ask the patient to identify it. If the facial nerve is working correctly, the patient will correctly identify the salt or sugar. If there is dysfunction of the facial nerve the patient will not have a sense of taste.

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