Asked by Stephen Blaze
Taste buds are sensory organs that are found in the little bumps (or papillae) on the tongue. The tongue contains about 8,000 taste buds and they’re replaced approximately every two weeks. Sensitive microscopic hairs on the taste buds (microvilli) pick up dissolved chemicals from food and send electrical signals to the brain that distinguishes between ﬁve different tastes: sweet, bitter, savoury (umami), salty and sour. Varying sensitivity to these tastes occurs across the whole of the tongue. But taste buds alone cannot tell us the exact ﬂavour of food. Other factors such as smell, spiciness, temperature and texture also contribute to the eventual taste. So if you hold your nose while you eat then your brain won’t get the full taste story!
Scout Davies, Science Museum