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 is red in colour. If you examine it minutely, you will see granular lumps on its upper surface.
They are called taste buds. These taste buds are composed of cells. There are hair-like fibres coming out of their upper ends.

    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 for the sour taste. The central portion is not sensitive for any taste because it does not have taste buds.

    The taste of food is known only when it is 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 generates nerve impulses. These impulses reach the 'taste centre' in the brain which ultimately gives the feeling of the taste. In addition to the tongue, other senses also help in the perception of the taste of food. The smell is also a part of the taste and felt by the nose. It is why one does not enjoy the total taste of food when one suffers from cold or influenza.

    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 3000 taste buds. However, with the advancement in age, the taste buds start losing vitality and finally become almost inactive. The number of taste buds is reduced to just 400 in the case of a seventy year old man.

    Due to constipation or indigestion, some impurities deposit on the tongue and they prevent the food particles from reaching the taste buds. Hence the taste of the food seems to be changed. Body fever and hot food also deactivate the taste buds and thus the food does not give its real taste.

    In the case of winecocoa and fruit juices, it is the smell which helps in the realisation of the real taste. When these liquids are taken into the mouth, the tongue expeiences the taste while their smell enters the nose and through the 'smell nerves' it reaches the brain. In this way he total pleasure of the taste is derived.