Which nerve provides motor innervation to the cricothyroid muscle?

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The motor supply to the cricothyroid muscle comes from the external branch of the superior laryngeal nerve. This branch of the vagus travels with the superior laryngeal artery and pierces the cricothyroid to deliver its motor fibers, which is exactly what enables cricothyroid to tense and lengthen the vocal folds by tilting the thyroid cartilage forward. The internal branch of the superior laryngeal nerve, in contrast, provides sensory innervation to laryngeal mucosa above the Vocal cords. The recurrent laryngeal nerve supplies all the other intrinsic laryngeal muscles, not cricothyroid. The hypoglossal nerve innervates tongue muscles, not the larynx. Thus, the external branch of the superior laryngeal nerve is the correct motor source for cricothyroid.