This organ is a mass of interwoven, striated muscle tissue interspersed with glands and fat and covered with a mucous membrane. The top surface contains numerous projections of the mucous membrane called papillae, which contain taste buds. Taste is one of two major forms of chemoreception that are part of the human experience, the other being smell. Taste buds are located in different areas of the tongue but are generally found around the edges. They are sensitive to five main tastes: bitter, sour, salty, sweet, and umami (the taste associated with mono-sodium glutamate, or MSG).