Oral Cavity 08

In this photomicrograph of a section of tongue, a portion of a circumvallate papilla is to the right and the fluid-filled trench (or moat) that surrounds it runs down the center of the field. Each oval structure labeled "T" is a taste bud and the horizontal line next to the upper taste bud points to the taste pore, by which the cells of the taste bud are in contact with fluid in the trench and the rest of the oral cavity. Although these features are hard to distinguish here, each taste bud contains three types of cells: (1) darker columnar sustentacular cells, (2) lighter columnar sensory cells, and (3) smaller basal cells, from which damaged sensory cells can be regenerated. Note the subtle differences between the cellularity of the taste buds and that of nearby connective tissue papillae (P), which produce invaginations of the surface epithelium, but do NOT lie within the basement membrane of the epithelium. Because the taste buds DO lie within the epithelium, the nerve fibers that contact the sensory cells of the taste buds must cross the basement membrane of the epithelium in order to synapse on the sensory cells.

Slide N-5, field N28,1 of finder slide B, 16X objective