THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -Mechanical digestion in the oral cavity consists of grinding of food into smaller pieces by the teeth, a process called mastication. Chemical digestion in the mouth is minor but consists of salivary amylase (ptyalin, or alpha-amylase) and lingual lipase, both contained in the saliva.

Detailed explanation-2: -Within the mouth, the teeth and tongue begin mechanical digestion. Other accessory organs add secretions (enzymes) that catabolize food into nutrients. Accessory organs include salivary glands, the liver, the pancreas, and the gallbladder.

Detailed explanation-3: -Mechanical digestion begins in your mouth with chewing, then moves to churning in the stomach and segmentation in the small intestine. Peristalsis is also part of mechanical digestion.

Detailed explanation-4: -The oral cavity is bounded by the teeth, tongue, hard palate, and soft palate. These structures make up the mouth and play a key role in the first step of digestion: ingestion.