Digestion is the process of breaking down food into smaller molecules that can be absorbed into the bloodstream. 1. Ingestion: Food is taken into the body through the mouth. 2. Mechanical Digestion: Food is physically broken down into smaller pieces by chewing (mastication) in the mouth and churning in the stomach. 3. Chemical Digestion: Enzymes and acids break down complex food molecules (carbohydrates, proteins, fats) into simpler ones. This begins in the mouth with saliva, continues in the stomach with stomach acid and enzymes, and is completed in the small intestine with enzymes from the pancreas and intestinal wall, and bile from the liver. 4. Absorption: The small molecules (like glucose, amino acids, fatty acids) pass through the walls of the small intestine into the bloodstream or lymphatic system. 5. Elimination: Undigested material and waste products are expelled from the body as feces.