The tongue is a muscular organ inside the mouth covered by thousands of small bumps called papillae, on which sit our taste buds, according to WebMD. The American Academy of Otolaryngology website says that smell and taste buds belong to our chemical sensing system.
Each taste bud is made of a collection of nerve cells that link to the brain, explains WebMD. Humans have several thousand taste buds, notes the U.S. National Library of Medicine. Children have a about 10,000 taste buds, according to KidsHealth. As people age, the number decreases to about 5,000 working taste buds. Some of them are then replaced in later age. Taste and smell cells are the only ones in the nervous system that have the ability to re-grow as they age.
The four main taste sensations that the tongue can identify are: sweet, sour, salty, and bitter. Molecules are released onto the tongue when we eat food, notes the American Academy of Otolaryngology. The full sensation of a taste is the combination of the signals from all the taste buds, notes the U.S. National Library of Medicine. Taste buds react to the molecules and then transmit the message to the brain. When a person smokes, the taste buds may become less able to identify different flavors.