Which muscle is innervated by the external branch of the superior laryngeal nerve?

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The external branch of the superior laryngeal nerve supplies motor innervation to the cricothyroid muscle. This nerve travels with the superior laryngeal artery and reaches the cricothyroid through the thyrohyoid membrane, where it enables the muscle to tense the vocal cords by tilting the thyroid cartilage forward, increasing pitch. Among the options, cricothyroid is the only intrinsic laryngeal muscle powered by this nerve; the thyrohyoid is innervated by C1 fibers via the hypoglossal nerve, and the inferior pharyngeal constrictor and cricopharyngeus are mainly innervated by the pharyngeal plexus from the vagus.