CH 11 DIGESTIVE SYSTEM

Molars are the last three teeth on each side of each jaw. They have a larger surface than the premolars. They are the principal grinders and crushers of food.

Premolars are two on each side in each jaw next to the canines. Each premolar has two hill-like projections. They help in grinding and crushing the food.

Canines are one on either side of the incisors in each jaw. These are conical and sharply pointed for holding and tearing the food.

Incisors are the front teeth in the centre of each jaw. Their cutting edges are broad and sharp like a chisel. They are used for biting and cutting.

There are four types of teeth in humans:- Incisors Canines Premolars Molars

The teeth cut and break the food into smaller bits.

The mouth or the oral cavity is the space where the food is chewed and mixed with saliva.

The alimentary canal is a muscular tube that starts with the mouth and ends at the anus.

The characteristics of an enzyme are:- It is a protein and is, therefore, destroyed by heating. It only affects the rate of a chemical reaction and always speeds up the reaction. It always forms the same end product from the substrate.

Enzymes play a vital role in the digestion of food.