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Taste buds are organs on your tongue that respond to chemical reactions from all the foods you eat. These chemicals dissolve in the saliva. The taste buds are tiny specks on the tongue. They send information detected by clusters of various receptors and ion channels to the gustatory cortex of the llama it up cerebrum via the seventh, ninth and tenth cranial nerves. Receptors on the surface of the tongue respond to different substances.

The human tongue has about 10,000 taste buds.
majority of taste buds on the tongue sit on raised protrusions of the tongue surface called papillae.






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Taste buds are organs on your tongue that respond to chemical reactions from all the foods you eat. These chemicals dissolve in the saliva. The taste buds are tiny specks on the tongue. They send information detected by clusters of various receptors and ion channels to the gustatory cortex of the llama it up cerebrum via the seventh, ninth and tenth cranial nerves. Receptors on the surface of the tongue respond to different substances.

The human tongue has about 10,000 taste buds.

Types of papillae

The majority of taste buds on the tongue sit on raised protrusions of the tongue surface called papillae. There are four types of papillae present in the human tongue:
  • Fungiform papillae - as the name suggests, these are slightly mushroom
    Mushroom

    A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name "mushroom" is the cultivated white button mushroom, Agaricus bisporus, hence the word mushroom is most often applied to those fungi that have a stem , a cap , and gills on the unde...
     shaped if looked at in longitudinal section. These are present mostly at the apex (tip) of the tongue, as well as at the sides. Innervated by facial nerve.
  • Filiform papillae - these are thin, long papillae "V"-shaped cones that don't contain taste buds but are the most numerous. These papillae are mechanical and not involved in gustation. Characterized increased keratinization.
  • Foliate papillae
    Foliate papillae

    Taste-buds, the end-organs of the gustatory sense, are scattered over the mucous membrane of the mouth and tongue at irregular intervals. They occur especially in the sides of the vallate papillae....
     - these are ridges and grooves towards the posterior part of the tongue found on lateral margins. Innervated by facial nerve (anterior papillae) and glossopharyngeal nerve (posterior papillae).
  • Circumvallate papillae
    Circumvallate papillae

    The circumvallate papillae are of large size , and vary from eight to twelve in number.They are situated on the dorsum of the tongue immediately in front of the foramen cecum and Terminal sulcus , forming a row on either side; the two rows run backward and medially, and meet in the midline, like the limbs of the letter V inverted....
     - there are only about 3-14 of these papillae on most people, and they are present at the back of the oral part of the tongue. They are arranged in a circular-shaped row just in front of the sulcus terminalis of the tongue
    Terminal sulcus (tongue)

    The dorsum of the tongue is convex and marked by a median sulcus, which divides it into symmetrical halves; this sulcus ends about 2.5 cm. from the root of the organ, in a depression called the foramen cecum, from which a shallow groove, the terminal sulcus, runs laterally and forward on either side to the margin of the tongue....
    . They are associated with ducts of Von Ebner's glands
    Von Ebner's glands

    Von Ebner's glands are named after Victor von Ebner, who was an Austrian histologist.These glands are located around circumvallate and foliate papilla in the tongue, and they secrete lingual lipase, beginning the process of lipid hydrolysis in the mouth....
    . Innervated by the glossopharyngeal nerve.


It is known that there are five taste sensations:
  • Sweet
    Sweetness

    Sweet is one of the five basic tastes and is almost universally regarded as a pleasure experience. Foods rich in simple carbohydrates such as sugar are those most commonly associated with sweetness, although there are other natural and artificial compounds that are much sweeter, some of which have been used as sugar substitutes for those wi...
    , Bitter, and Umami
    Umami

    is one of the five Taste#Basic taste sensed by specialized receptor cells present on the human tongue. Umami is a loanword from Japanese language meaning roughly "delicious flavor", although "brothy", "meaty", or "savory" have been proposed as alternate translations....
     (now sometimes called Savory), which work with a signal through a G-protein coupled receptor.
  • Salty and Sour, which work with ion channel
    Ion channel

    Ion channels are pore-forming proteins that help establish and control the small voltage gradient across the plasma membrane of all living cell s by allowing the flow of ions down their electrochemical gradient....
    s.


Localization of taste and the human "tongue map"

Contrary to popular understanding that different tastes map to different areas of the tongue, taste qualities are found in all areas of the tongue, although some regions are more sensitive than others.

The original "tongue map
Tongue map

A tongue map or taste map is a schematic map of the tongue, in which each part of the tongue is associated with a Taste#Basic taste. The theory behind this map, disproven by later research, is that certain parts of the tongue are exclusively responsible for tasting a certain basic taste....
" was based on a mistranslation by Harvard psychologist Edwin G. Boring
Edwin G. Boring

Edwin Garrigues Boring was an Experimental psychology who later became one of the first historians of psychology....
 of a German paper that was written in 1901. Varying sensitivity to all tastes occurs across the whole tongue and indeed to other regions of the mouth where there are taste buds (epiglottis, soft palate).

Structure of taste buds

Each taste bud is flask-like in shape, its broad base resting on the corium, and its neck opening, the gustatory pore, between the cells of the epithelium.

The bud is formed by two kinds of cells: supporting cells and gustatory cells.

  • The supporting (sustentacular) cells are mostly arranged like the staves of a cask, and form an outer envelope for the bud. Some, however, are found in the interior of the bud between the gustatory cells.


  • The gustatory (taste) cells, a chemoreceptor, occupy the central portion of the bud; they are spindle-shaped, and each possesses a large spherical nucleus near the middle of the cell.


The peripheral end of the cell terminates at the gustatory pore in a fine hair-like filament, the gustatory hair.

The central process passes toward the deep extremity of the bud, and there ends in single or bifurcated varicosities.

The nerve fibrils after losing their medullary sheaths enter the taste bud, and end in fine extremities between the gustatory cells; other nerve fibrils ramify between the supporting cells and terminate in fine extremities; these, however, are believed to be nerves of ordinary sensation and not gustatory.

See also

  • Taste
    Taste

    Sorry, no overview for this topic
  • Gustatory System
    Gustatory system

    The gustatory system is the sensory system for the sense of taste....


Additional images


External links

  • from National Public Radio's Talk of the Nation, July 22, 2005