Comments

Saliva and peristalsis


THE salivary amylase digests starch and other polysaccharides (such as glycogen), reducing them to maltose (disaccharide) molecules.

Salts, in saliva, neutralize acidic substances and maintain a slightly acidic pH in the mouth (6, 7), ideal for the action of ptialin. The food, which becomes a food bolus, is pushed by the tongue to the bottom of the pharynx, and is sent to the esophagus, driven by peristaltic waves (as shown in the picture below), taking between 5 and 10 seconds to travel through the esophagus.

Through peristalsis you can be turned upside down and yet your food will reach the gut.

A mechanism to close the larynx kicks in, preventing food from entering the airways. When the cardia (muscle ring, sphincter) relaxes, allows food to pass into the stomach.