Damage to which cranial nerve may result in difficulty swallowing (dysphagia) and loss of taste in the posterior third of the tongue?

Damage to which cranial nerve may result in difficulty swallowing (dysphagia) and loss of taste in the posterior third of the tongue?

• A. Trigeminal Nerve
• B. Facial Nerve
• C. Vagus Nerve
• D. Glossopharyngeal Nerve

Answer: (C)

Taste and swallowing are controlled by specific cranial nerves, and one nerve in particular handles both the sensation from the back of the tongue and a key muscle involved in swallowing. The posterior third of the tongue carries taste fibers in association with the glossopharyngeal nerve, which also provides sensory input from the oropharynx and innervates the stylopharyngeus muscle that helps elevate the pharynx during swallowing. When this nerve is damaged, swallowing becomes difficult (dysphagia) and taste in the posterior third of the tongue is lost, which fits the clinical picture described. The vagus nerve can affect swallowing because it controls many pharyngeal and laryngeal muscles, but it does not carry taste from the posterior tongue. Taste from that region is specifically carried by the glossopharyngeal nerve, while the vagus handles taste from other areas like the epiglottis. So the combination of dysphagia with loss of taste in the posterior third of the tongue points to the glossopharyngeal nerve.

Taste and swallowing are controlled by specific cranial nerves, and one nerve in particular handles both the sensation from the back of the tongue and a key muscle involved in swallowing. The posterior third of the tongue carries taste fibers in association with the glossopharyngeal nerve, which also provides sensory input from the oropharynx and innervates the stylopharyngeus muscle that helps elevate the pharynx during swallowing. When this nerve is damaged, swallowing becomes difficult (dysphagia) and taste in the posterior third of the tongue is lost, which fits the clinical picture described.

The vagus nerve can affect swallowing because it controls many pharyngeal and laryngeal muscles, but it does not carry taste from the posterior tongue. Taste from that region is specifically carried by the glossopharyngeal nerve, while the vagus handles taste from other areas like the epiglottis. So the combination of dysphagia with loss of taste in the posterior third of the tongue points to the glossopharyngeal nerve.