a receptor cell for gustatory stimuli. Each has a hairlike extension (see microvillus) that protrudes from the opening in the taste bud. Humans have about 300,000 taste cells, though the number can vary across individuals, and there are about 50 cells per taste bud. Taste cells can be divided into four anatomical types: Type I cells comprise 60% of the total, Type II cells 20%, Type III cells 15%, and Type IV cells 5%. All but Type IV cells may be involved in taste transduction. See also gustatory neuron types.