How does the tongue tell us the taste ?

   How does the tongue tell us the taste ?
  
   Man has five senses of perception - eyes, nose, ears, 
   Skin and tongue. The tongue tells the taste. 
   The tongue is located inside the mouth . It is narrow 
   In the front side , While broader in the rear. It is an
   important muscle in the body. It's red in  colour . 
   You will see granular lumps on its upper Surface . 
   They are called as taste buds .These taste buds are 
   are composed of cells. There are hair like fibers  
   

These taste buds are of four kinds , telling us four main tastes - Sweet , bitter , sour and salty             

The front portion of the tongue is sensitive for      

Sweet and salty tastes , the back portion is for the

 bitter and the edges of the tongue are the sour      

taste. The central portion is not sensitive for any 

taste because it does not have taste buds .             

The taste of food is know only when it's in liquid 

State. A portion of the food is dissolved in saliva 

which activates the taste buds.                                 

A chemical reaction produced by the food material 

generate nerve impulses. These impulses reach the 

' taste buds ' in the brain which ultimately gives the 

feeling of the taste . The smell is also a part of the   

taste and felt by the nose .                                            

The number of taste buds on the tongue of an adult

is more than on that of a child .The tongue of an     

adult has about 2000- 8000 taste buds .                       

The number of taste buds is reduced to just 400 in 

case of a seventy year old man.                                    

It does not enjoy the total taste of food when suffer 

from cold or influenza.                                                   

Hence the taste of the food seems to be changed      

When body fever and hot food also deactivate the   

taste buds and the food does not give it's real taste.