Anatomy of Taste Buds

Anatomy of Taste Buds The oral cavity and its anatomy play a key role in understanding taste and its biological function in the human body. The oral cavity consists of your lips, cheeks, teeth, tongue and throat. The taste buds are the chemoreceptors that detect and relay taste stimuli. In order for the taste buds to detect the taste of food or drink, the molecule must be suspended in an aqueous solution, otherwise known as saliva. Most taste buds are found within specialized projections on the tongue called papillae (Seeley, Stephens, they do not house taste buds but they do provide the rough surface on the tongue that allows for easier manipulation of food (Seeley, Stephens, â€Å"Eight to 12 of these papillae form a V-shaped row along the border between the anterior and posterior parts of the tongue† (Seeley, Stephens, & Tate, 2008). Each person has roughly 10,000 taste buds on their tongue, and each taste bud contains three distinct types of specialized epithelial cells within them. â€Å"T he sensory cells of each taste bud consist of about 50 taste, or gustatory cells. The remaining two cell types, which are nonsensory cells, are basal cells and supporting cells† (Seeley, Stephens, & Tate, 2008). Each taste cell has gustatory hairs, which are specialized microvilli, that help direct the tastants, or substances dissolved in saliva, into the taste, or gustatory, pore (Seeley, Stephens, & Tate, 2008). Several secondary sensory neurons connect to each taste bud and release neurotransmitters when stimulated. Sensory information from the oral cavity can travel to the brain in three different ways. The tongue itself is broken down into thirds. Sensory information from the anterior, or front, two-thirds of the tongue is transmitted to the brain via a branch of the facial nerve (cranial nerve VII) called the chorda tympani (Seeley, Stephens, & Tate, 2008). Information from the posterior, or back, one-third of the tongue, the circumvallate papillae, and the superior phar ynx is carried by the glossopharyngeal nerve (cranial nerve IX) (Seeley, Stephens, & Tate, 2008). The vagus nerve (cranial nerve X) transmits information from the epiglottis, which is located in the back of the throat (Seeley, Stephens, & Tate, 2008). The olfactory region also has a substantial role in taste so it warrants a brief anatomical discussion as well. Olfaction is our sense of smell and it is a response to odorants that stimulate sensory receptors that are located in the extreme superior region of the nasal cavity (Seeley, Stephens, & Tate, 2008). The ten million olfactory neurons that are located in the olfactory region of the nasal cavity then travel through foramen in the cribriform plate of the ethmoid bone in the bottom of the skull and terminate into the olfactory bulb that’s just above the cribriform plate (Seeley, Stephens, & Tate, 2008). The olfactory tract then takes the signal from the olfactory bulb to the cerebral cortex (Seeley, Stephens, & Tate, 2008) . This is a simplified version of the much more complex biological process that is olfaction, but it is sufficient for the depth of this paper.