ANATOMY

Detailed explanation-1: -No digestion occurs in the esophagus. After passage through the esophagus, the bolus will enter the stomach and undergo mechanical and chemical digestion. Mechanical digestion in the stomach occurs via peristaltic contractions of the smooth muscle from the fundus towards the contracted pylorus, termed propulsion.

Detailed explanation-2: -Most mechanical and some chemical digestion occur in the stomach. Mechanical digestion occurs as layers of muscle in the stomach lining contract to produce a mixing and churning motion. Chemical digestion is carried out by stomach juices that contain enzymes and hydrochloric acid.

Detailed explanation-3: -Both mechanical and chemical digestion occur in the mouth. Teeth grind and break up food (mechanical), while an enzyme in saliva called amylase begins to break down carbohydrates (chemical). After it is swallowed, the chewed food (now called a bolus) moves down the esophagus.

Detailed explanation-4: -The chemical digestion of proteins begins in your stomach. Carbohydrate and lipid digestion continues in the stomach (lipids are the chemical components of fat). Your stomach releases gastric juices that begin to break down all of the food you’ve eaten.