Digestive System:Mouth

The mouth is the start of the digestive system. The mouth consist of saliva, teeth and a tongue.

Teeth:

A human usually have 20 baby teeth, and 32 adult teeth. There are 4 types of teeth.

1. Incisors: They are the front teeth that is used to bite of large food items. Humans normally have 8 incisors teeth
2. Canines: They are the teeth behind the incisors that is used to tear through food. It is taller and more pointed compared to the incisors. Humans normally have 4 canine teeth.
3. Pre-molars: They are the teeth in between the canine and the molars. It is used for crushing the food into bits, it is also wider den the incisors and canines teeth. Humans normally have 8 pre-molars.
4. Molars: They are the utmost rear teeth and are used for chewing,they are also the broadest teeth. Adult humans have twelve molars, in four groups of three at the back of the mouth. The third rearmost molar in each group is called a wisdom tooth.

Saliva:

Saliva contains a type of enzyme called amylase. This enzyme breaks apart starch. This is why when we chew starchy foods like bread, potatoes, pasta or rice, we can sometimes taste them becoming sweeter.

Tongue:

The tongue taste food so that we know what we are eating. It can tell us when a food is rotten when it taste bitter. The tongue also shifts bits of food stuck among the teeth.

The food, after chewed into soft paste, will continue down to the gullet.