The anatomy and physiology of the mouth and its role in the process of digestion... This involves the teeth in mechanical digestion, the anatomy of the tongue and the role it plays in taste as well as bolus formation and swallowing. The salivary glands, their chemical makeup and how they affect both chemical digestion and swallowing, as well as the part played by the palate and the pharynx in reflex swallowing. We discussed peristalsis in the esophagus and how this moves the partially digested food toward the stomach, no matter what position the body is in.