A Taste Bud Taste buds stud the bumps (papillae) on the tongue, shown here, as well as the back, sides, and roof of the mouth (a). Each taste bud contains a range of receptor cells that respond to varying chemical components of foods called tastants (b). Tastant molecules dissolve in saliva and stimulate the microvilli that form the tips of the taste receptor cells (c). Each taste bud contacts the branch of a cranial nerve at its base.