Digestion involves breaking down large food molecules, but before chemical digestion can be efficient, the food needs to be broken into smaller pieces. This process is called physical digestion.

Imagine trying to dissolve a large sugar cube versus granulated sugar. The granulated sugar dissolves faster because it has a larger surface area. Physical digestion works on the same principle: breaking food into smaller pieces increases the surface area for digestive enzymes to work on, speeding up chemical digestion.

Physical digestion begins in the mouth with the teeth. There are four main types of teeth in humans, each adapted for a different role: incisors, canines, premolars, and molars.

At the front of your mouth are the incisors. They are sharp and chisel-shaped, perfect for biting and cutting pieces of food, like when you bite into an apple.