DIGESTION IN ORAL CAVITY

Food inters into the digestive tract through the oral cavity. The oral cavity consists of many important structures like palate, tongue, teeth and opening of salivary glands. Each part performs a specific function.

                Four function are performed by the oral cavity.

 

1.   Selection of Food            

2.   Grinding of Food

3.   Lubrication

4.   Digestion
 

                  SELECTION OF FOOD

 

First function of oral cavity is too select the food by taste. A food with bat taste is rejected. In the selection of food sight and smell plat an important role. Social and psychological factors are also involved in preferring a certain type of food over the other.

 

                       GRINDING OF FOOD

 

Once the food is inside the mouth cavity, it is subjected to the grinding action. Teeth, tongue and cheeks all take part in the physical and quick breakdown of food into smaller pieces. Enzymes can easily work on smaller food particles.

 

3                     LUBRICATION AND DIGESTION

 

The process of lubrication and digestion starts as the food is broken down into smaller pieces. Three pairs of the salivary glands secrete saliva which has three ingredient;

 

1.   Water and mucus

2.   Sodium bicarbonate and other salts

3.   Enzyme-Amylase or ptyalin

 

Water And Mucus

                 Water and mucus together make slimy liquid which mainly moistens and lubricates the ingested food. Thus food can be chewed efficiently to allow the digestive juices to inter the food mass.

 

            Sodium Bicarbonate

               Sodium bicarbonate and other salts stabilize the pH of the food although they are slightly antiseptic. Fresh saliva is alkaline with a pH 8 but quickly loses carbon dioxide and gets to pH6.

 

           Amylase

               Amylase (Ptyalin) is a carbohydrate enzyme which hydrolyzes starch and glycogen to maltose. Thus softened, partially digested food is now arranged into small oral lumps called boluses. The boluses are pushed to pharynx by the combined efforts of the cheek muscles, the floor of the buccal cavity and the tongue.