The tongue is innervated by four cranial nerves, the fifth or trigeminal, the seventh or facial, the ninth or glossopharyngeal, and the twelfth or hypoglossal. The trigeminal nerve supplies the anterior two thirds of the tongue and is concerned with general sensibility. The facial nerve serves the same region but is concerned with taste or gustatory sensibility. The posterior one third of the tongue is innervated by the glossopharyngeal nerve serving both general and gustatory sensibility.
General sensibility refers to touch, pressure, pain, temperature, sense of position, and movement.
Taste or gustatory sense, smell, sight, hearing, and awareness of head position and movement are termed the special senses. Larger than the filiform papillae. Wider at the top than at the base, resembling a mushroom, hence their name. Epithelial covering may possess taste buds. Threadlike papillae much more numerous and smaller than fungiform papillae.