Which structure uses only mechanical digestion food? (peristalsis only) liver esophagus stomach large intestine

The answer is **esophagus**.<br /><br />Here's why:<br /><br />* **Mechanical digestion** involves physically breaking down food into smaller pieces. Peristalsis, the rhythmic muscular contractions that move food through the digestive tract, is a form of mechanical digestion.<br /><br />* The **esophagus** *only* uses peristalsis to move food from the mouth to the stomach. No chemical digestion occurs here.<br /><br />* The **stomach** uses both mechanical (churning) and chemical digestion (acids and enzymes).<br /><br />* The **large intestine** primarily focuses on water absorption and waste compaction, but some bacterial digestion (chemical) does occur.<br /><br />* The **liver** produces bile, which is important for *chemical* digestion of fats in the small intestine, but the liver itself doesn't perform mechanical digestion.<br />