Which nerve is primarily responsible for sensation to the anterior two-thirds of the tongue when numbness persists?

Which nerve is primarily responsible for sensation to the anterior two-thirds of the tongue when numbness persists?

• A. Lingual nerve
• B. Hypoglossal nerve
• C. Glossopharyngeal nerve
• D. Trigeminal motor root

Answer: (A)

General sensation to the anterior two-thirds of the tongue is carried by the lingual nerve, a branch of the mandibular division of the trigeminal nerve. This nerve supplies touch, pressure, and temperature to that portion of the tongue, so persistent numbness in that area points to involvement of the lingual nerve. The glossopharyngeal nerve handles the posterior one-third of the tongue, the hypoglossal nerve controls tongue movement (not sensation), and the trigeminal motor root is mainly a motor pathway. A useful related note: taste from the anterior two-thirds travels with the lingual nerve via the chorda tympani, but taste and general sensation are carried by different fibers.

General sensation to the anterior two-thirds of the tongue is carried by the lingual nerve, a branch of the mandibular division of the trigeminal nerve. This nerve supplies touch, pressure, and temperature to that portion of the tongue, so persistent numbness in that area points to involvement of the lingual nerve. The glossopharyngeal nerve handles the posterior one-third of the tongue, the hypoglossal nerve controls tongue movement (not sensation), and the trigeminal motor root is mainly a motor pathway. A useful related note: taste from the anterior two-thirds travels with the lingual nerve via the chorda tympani, but taste and general sensation are carried by different fibers.