A child is born with an anterior tongue that is covered by stratified squamous epithelium except for circumvallate papillae, which show a different epithelial lining. From which embryological structure does the posterior one-third of the tongue develop?

• A Hypobranchial eminence (copula) from second, third, and fourth pharyngeal arches ✓
• B Median tongue bud (tuberculum impar) from the floor of pharynx
• C Lateral lingual swellings from the first pharyngeal arch
• D Epiglottal swelling from the fourth and sixth pharyngeal arches

Explanation

The anterior two-thirds (oral part) of the tongue develops from the first pharyngeal arch: median tongue bud (tuberculum impar) and lateral lingual swellings. The posterior one-third (pharyngeal part) develops from the hypobranchial eminence (copula), formed by mesoderm of the second, third, and fourth pharyngeal arches — predominantly the third arch overgrows the second and fourth. The boundary between anterior two-thirds and posterior one-third is the sulcus terminalis (with foramen cecum at its apex, marking the site of thyroglossal duct origin). This dual origin explains why lingual carcinoma in the posterior one-third (CN IX sensory) drains differently from the anterior two-thirds (CN V3 sensory).

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.