Taste buds

Gustatory receptor cells are epithelial cells, however are excitable. They are organized into small clusters of 50–100 that, with supporting cells, form taste buds. The taste buds are situated in the epithelium of the palate, tongue, palate, pharynx, epiglottis, and the upper portion of the esophagus. In the tongue they are present in small projections, papillae. Microvilli on the apical border of each receptor cell project through taste pores in the gustatory epithelium fetching them into contact with the contents of the mouth. The microvilli are the taste organelles which are as shown in the figure below:

                                                                           Figure: A taste bud.

Receptor cells form synaptic connections with main gustatory afferents, each of which branches to synapse with receptor cells in more than one taste bud. The main afferent axons from palate, tongue, and pharynx enter the facial (VII) and glossopharyngeal (IX) nerves. Some of the afferent in epiglottis and esophagus are innervated by the vagus (X) nerve.