<prompt> If a person has normal musculature but has difficulty swallowing, which nerves should be tested for function?Hypoglossal and phrenicHypoglossal and splanchnicGlossopharyngeal and vagusSplanchnic and vagus  <response>: The upper 23 of the esophagus contains striated muscle. It is derived from the pharyngeal arches and innervated by the vagus nerve CN X. The lower 13 contains smooth muscleft from splanchnic mesoderm and is innervated by the splanchnic plexus. 