Where does digestion begin in the human body?

Digestion begins in the mouth, where mechanical and chemical processes start the breakdown of food. When food is chewed, it is mixed with saliva, which contains enzymes like amylase that initiate the chemical digestion of carbohydrates. The act of chewing reduces the food into smaller pieces, making it easier for the enzymes to work effectively. Saliva also lubricates the food, forming a bolus that can be swallowed.

After the mouth, the food travels down the esophagus to the stomach, where further digestion occurs, but the initial stages have already set the foundation for nutrient extraction. Therefore, the mouth is indeed the correct answer as it plays a critical role in the digestion process from the very start.