tongue

The tongue is a muscular, mucosa-covered organ located on the floor of the mouth. It plays a central role in taste, speech, food manipulation, swallowing, and oral hygiene.

Anatomy: The tongue contains intrinsic muscles for shaping and extrinsic muscles for movement (genioglossus, hyoglossus, styloglossus, palatoglossus). It has an anterior two-thirds (oral part) and a posterior one-third (pharyngeal part), with the base anchored to the hyoid bone. The dorsal surface bears papillae: filiform (mechanical), fungiform (taste buds scattered), circumvallate in a row at the back, and foliate on the sides. The undersurface is smooth, with a lingual frenulum attaching to the floor; the posterior part contains lymphoid tissue (lingual tonsils).

Innervation: Motor to intrinsic and most extrinsic muscles is provided by the hypoglossal nerve (XII); palatoglossus is supplied by the pharyngeal plexus from the vagus nerve (X). Sensory and taste: anterior two-thirds receive general sensation via the lingual nerve (branch of V3) and taste via chorda tympani (branch of VII); posterior one-third and the root receive general sensation and taste via IX; the epiglottis is served by X. Taste signals reach the gustatory cortex through the thalamus.

Clinical and functional notes: The tongue enables food manipulation, swallowing, speech, and oral cleansing, aided by saliva. Common conditions include ankyloglossia (tongue-tie), glossitis, fissured tongue, geographic tongue, and tongue cancer. Risk factors for malignancy include tobacco use, alcohol, and HPV infection; management ranges from observation and lifestyle modification to antifungal therapy, surgical procedures, or oncologic treatment as appropriate.