Taste Buds

About the Taste Buds

Taste buds are small clusters of specialized receptor cells, typically containing dozens of cells each, that detect chemicals dissolved in saliva. Most are located on the tongue within raised structures called papillae: fungiform papillae scattered over the front, foliate papillae along the sides, and the large circumvallate papillae arranged in a V near the back, while filiform papillae, the most numerous, contain no taste buds and give the tongue its rough texture. Taste buds are also found on the soft palate, pharynx, and epiglottis. Five basic tastes are widely recognized: sweet, sour, salty, bitter, and umami, the savory taste of glutamate, identified by Kikunae Ikeda in 1908. Sweet, umami, and bitter are detected by G protein coupled receptors, while salty and sour involve ion channels. The idea of a tongue map, with each taste confined to one region, is a long standing myth, as all tastes can be detected across the tongue. Taste cells are replaced every few weeks. Much of what is perceived as flavor actually depends on smell.