Anatomy/Digestive Secretion List

For the Digestive System page, see Anatomy/Digestive System

Various parts of the digestive tract secrete many enzymes and fluids. This page is a comprehensive list of those secretions, their source, and their functions.


 * Enzymes speed up digestive processes to make digestion faster.


 * Hormones can stimulate digestion, and the release of hormones into the organs.


 * Mucus can protect the inner wall of organs, as well as lubricating them for movement.

Other Secretions

 * Saliva is a fluid secreted by the salivary glands. It moistens and lubricates and has an optimum pH of 6.5-7.5.
 * Lysozyme is an enzyme secreted by the salivary glands. It kills bacteria.
 * Mucus is a fluid secreted by the foveolar cells in the stomach. It protects the stomach wall.
 * Chymosin is a fluid secreted by the chief cells of the stomach. It coagulates milk and has an optimum pH of 3.5.
 * Hydrochloric acid is a fluid secreted by the parietal cells of the stomach. It kills bacteria, activates pepsinogen -> pepsin, and lowers the pH of the stomach. Its acidity denatures proteins, aiding in protein digestion. It has a pH of 1.
 * Intrinsic factor is an enzyme (glycoprotein) secreted by the parietal cells of the stomach. It assists in the absorption of vitamin B12 by protecting the acid-intolerant substance as it goes through the stomach. It has an optimum pH of 7.
 * Bile is a fluid consisting primarily of bile salts and bilirubin produced by the hepatocytes of the liver and secreted by the gallbladder. It assists in the digestion of lipids and has an optimum pH of 7.5-8.8.
 * Bicarbonate ions are secreted by the pancreas. They are alkaline and are employed to control pH levels.