Which term describes the physical breakdown of foods such as chewing and mixing?

• A. Absorption
• B. Mechanical processing
• C. Secretion
• D. Ingestion

Answer: (B)

Mechanical processing describes the physical breakdown of foods through actions like chewing and mixing. This step reduces particle size and blends food with saliva, increasing surface area so enzymes can work more effectively later in digestion. In the mouth, teeth physically break down food, and the resulting mixture is formed into a bolus. In the stomach, muscular contractions churn and mix the contents, further breaking them apart without chemical changes.

Absorption is the uptake of nutrients across the intestinal lining after digestion has reduced the food to small molecules. Secretion refers to releasing digestive fluids such as saliva, gastric juice, or pancreatic juice. Ingestion is the act of taking food into the mouth. The physical breakdown described here fits best with mechanical processing because it focuses on the actual physical size reduction and mixing, not on nutrient uptake, fluid release, or the act of eating.