Which cranial nerve is designated as the tenth cranial nerve?

• A. Vagus
• B. Accessory
• C. Glossopharyngeal
• D. Hypoglossal

Answer: (A)

Understanding how cranial nerves are numbered helps here: the tenth cranial nerve is the vagus. It travels from the brainstem down into the chest and abdomen, providing parasympathetic control to the heart, lungs, and much of the gastrointestinal tract, and it carries sensory information from visceral organs. It also sends motor fibers to muscles involved in swallowing and speech via branches to the pharynx and larynx. The name “vagus” means wanderer, reflecting its long, far-reaching course. This extensive autonomic role plus its mixed sensory and motor functions distinguish it as the tenth nerve. (For comparison, the glossopharyngeal is involved with the throat and salivation, the hypoglossal controls the tongue, and the accessory moves neck/shoulder muscles.)