الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 114 |  |  |
| | | from | 114 | | |
Abstract
Taste buds are small dot like structures on the upper surface of the tongue, soft palate, upper esophagus and epiglottis that provide information about the taste of food being eaten. The human tongue has about 10,000 taste buds. The majority of them lies on raised protrutions of the tongue surface called papillae, which are well developed before full differentiation of taste bud cells within them. Taste buds composed of at least three cell classes: dark cells (Type I), light cells (Type II) and basal cells (stem) cells. Taste bud development within the gustatory papillae is essentially a postnatal process. However, recent experimental work has revealed that much of embryonic development of taste buds is actually nerve independent. This is further confirmed by recent gene expression studies in developing mouse embryos. Tissue-intrinsic mechanisms are responsible for generating and possibly patterning taste buds. The gene, SOX2, stimulates stem cells on the surface of the embryonic tongue and in the back of the mouth to transform them into taste buds. The sensation of taste has both cognitive and hedonic aspects. Several taste receptors have been identified within taste cell membranes on the surface of the tongue, and they include the T2R family of bitter taste receptors, the T1R receptors associated with sweet and umami taste perception