Describe the process of digestion that happens in the body, starting with someone taking a bite of food.

Mechanical digestions begins in your mouth as your teeth tear and grind food into small bits and pieces you can swallow without chocking. The muscular walls of your esophagus, stomach, and intestines continue mechanical digestion, pushing the food along, churning and breaking it into smaller particles. 

Chemical digestion occurs at every point in the digestive system, beginning when you see, or smell food. These sensory events set off nerve impulses of enzymes and other substances that will eventually break down food to release the nutrients inside. The body then burns these nutrients for energy or uses them to build new tissues and body parts.