Recall where digestion begins.

Digestion begins in the mouth. Here's a step-by-step breakdown:

1. The process starts with the intake of food. The food is broken down into smaller pieces by the process of mastication (chewing).

2. Saliva, produced by the salivary glands in the mouth, is mixed with the chewed food. Saliva contains an enzyme called amylase that starts the breakdown of carbohydrates in the food.

3. The tongue helps in mixing the food with saliva and forms it into a bolus (a small rounded mass of chewed food).

4. The bolus is then swallowed and travels down the esophagus to the stomach through the process of peristalsis (muscle contractions).

So, the digestion process begins in the mouth with the physical breakdown of food by chewing and the chemical breakdown by enzymes in saliva.