system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
If a person has normal musculature but has difficulty swallowing, which nerves should be tested for function?
assistant
The correct answer is  The upper 2/3 of the esophagus contains striated muscle. It is derived from the pharyngeal arches and innervated by the vagus nerve (CN X). The lower 1/3 contains smooth muscleft from splanchnic mesoderm and is innervated by the splanchnic plexus.