Which laryngeal muscle is tested for motor function because its function (or lack thereof) will provide an understanding of swallowing sensory integrity?

• A. Thyrocricoid
• B. Cricothyroid
• C. Arytenoids
• D. Cricoarytenoid

Answer: (B)

The main idea is to assess the superior laryngeal nerve (SLN) function by testing a muscle that is uniquely innervated by its external branch. The cricothyroid is the only intrinsic laryngeal muscle supplied by the external branch of the SLN. If cricothyroid movement can be elicited, it indicates the external SLN is intact. Since the SLN carries sensory fibers that contribute to swallow safety (via its internal branch), confirming the motor function of cricothyroid provides a practical proxy that the nerve pathway involved in swallowing sensation is preserved. In contrast, the other options are controlled by the recurrent laryngeal nerve or are not specific muscle targets for SLN motor testing, so they don’t specifically inform about swallowing sensory integrity.