A sensory nerve block is placed at the base of a tongue lesion prior to biopsy. Which nerve was anesthetized to provide pain relief?

Correct answer: A. Lingual nerve (branch of CN V3)

• A. Correct. The LINGUAL NERVE (a branch of the mandibular division of CN V3) provides general somatic SENSORY innervation (touch, pain, temperature) to the anterior two-thirds of the tongue. Blocking it at the tongue base produces anesthesia for biopsy.
• B. Incorrect. CN IX provides sensory innervation to the POSTERIOR one-third of the tongue — not the standard block for anterior/lateral tongue biopsy.
• C. Incorrect. The chorda tympani carries taste from the anterior tongue (joining the lingual nerve) and parasympathetic fibers — not the general pain sensation nerve.
• D. Incorrect. The hypoglossal nerve (CN XII) is the MOTOR nerve of the tongue — it has no sensory function.