The Process of Taste

How We Taste

            Taste is our gatekeeper to the enjoyment of food.  It also helps us to determine which substances we should consume and which we should avoid.  A person has approximately 10,000 taste buds with each bud containing 50-100 taste cells, which have tips that protrude into the taste pore.  Taste buds are generally replaced every 10 days.  Most are on the tongue but some are located in the back of the throat.  Grouped together in bumps or papillae on the surface of the tongue, the taste buds contain receptors that respond to four basic tastes: sweet, salty, sour, and bitter.  The number and density of taste buds a person has determines the sensitivity to each taste.  This is also known as being a taste or non-taster.  Normally, a greater response is found in more bitter substances.   Each receptor responds most strongly to one or two of the four basic tastes and slightly to the others.  The taste cells work together to generate a unique pattern of electrical signals that are transmitted to the brain for each substance tasted.  When a person tastes, chemical stimuli produce connections in the brain stem in the nucleus of the solitary tract are acquired from fibers found on the tongue, mouth and throat.  These signals then travel to the thalamus and extend to the frontal lobe (insula) and the frontal operculum cortex.  The sense of smell often works in conjunction with our sense of taste by combining sensations to achieve the perception of flavor. In fact, the olfactory sense actually contributes more to the perception of specific flavors than does the sense of taste.

The ‘geusia’s

            Could you imagine not having the ability to taste?  Ageusia is a disorder of the chemosensory organ of taste.  This is when a person has no ability to taste due to the tongues loss of function to taste or feel any taste.  Since smell and taste go hand in hand, this person may have also lost their sense of smell.  The tongue can only feel the texture and therefore the person feels the taste of the flavor only after both sense organs (nose and tongue) function properly.  Ageusia is a very rare condition whereas most patients suffer from hypogeusia whereas there is a loss of taste sense causing reduced intensity or dysgeusia which is a distortion of taste and the inability to differentiate between tastes (mistake salty for sour).  Causes of these disorders are primarily due to damage of the nervous system.  This would entail damage to the nerves of the tongue (lingual  and glossopharyngeal nerve).  Other causes could be multiple sclerosis and infectious conditions.