A medical student is asked to explain the nerve supply of the tongue. General sensation and taste from the posterior one-third of the tongue are carried by the glossopharyngeal nerve. This territory corresponds developmentally to the:

• A Lateral lingual swellings of the first arch
• B Epiglottic swelling of the fourth arch
• C Hypobranchial eminence contribution of the third arch ✓
• D Tuberculum impar of the first arch

Explanation

The posterior one-third of the tongue comes mainly from the third arch component of the hypobranchial eminence, so its mucosa is innervated by the nerve of the third arch, the glossopharyngeal. The anterior two-thirds arise from lateral lingual swellings and tuberculum impar of the first arch, explaining trigeminal and chorda tympani supply there. The epiglottic swelling of the fourth arch supplies only the extreme posterior base and valleculae.

Reference: Langman's Medical Embryology, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.