A tongue is a muscular organ in the mouth of most vertebrates, including humans. It is primarily used for tasting, chewing, and swallowing food, as well as for speech in humans. The tongue is made up of various muscles, nerves, and tissues, and it is highly flexible, allowing for a wide range of movements necessary for its functions. Additionally, the surface of the tongue is covered with tiny structures called papillae, which contain taste buds that enable the perception of different tastes such as sweet, sour, salty, bitter, and umami.