Here's why:

* Food Intake: The mouth is where food enters the body.

* Mechanical Digestion: Chewing in the mouth begins the mechanical breakdown of food.

* Chemical Digestion: Saliva, produced in the mouth, contains enzymes that start the chemical digestion of carbohydrates.

The alimentary canal, also known as the digestive tract, is a continuous tube responsible for breaking down food into smaller molecules that the body can absorb and use for energy and building blocks.