Taste bud. Coloured scanning electron micrograph (SEM) of a taste bud (centre) from a tongue. This is part of a tongue structure called a fungiform papilla. These are round structures on the tongue surface, and are less numerous than the elongated filiform papillae (not seen). The tongue papillae are covered by the scaly squamous epithelial cells seen surrounding this central taste bud. The taste bud itself is a neuro-epithelial cell that reacts to chemicals in food, transmitting nerve impulses to the brain. These impulses are processed to form the sensation of taste. Magnification unknown.