To Understand the Causes of Gastritis, One Must Know Anatomy and Physiology (Part 2)

Glands responsible for digestion

The glands that act first are in the mouth—the salivary glands. Saliva produced by these glands contains an enzyme that begins to digest the starch from food into smaller molecules.

The next set of digestive glands is in the stomach lining. They produce stomach acid and an enzyme that digests protein. One of the unsolved puzzles of the digestive system is why the acid juice of the stomach does not dissolve the tissue of the stomach itself. In most people, the stomach mucosa is able to resist the juice, although food and other tissues of the body cannot.

• Mucus: The most abundant epithelial cells are mucous cells, which cover the entire lumenal surface and extend down into the glands as "mucous neck cells". These cells secrete a bicarbonate-rich mucus that coats and lubricates the gastric surface, and serves an important role in protecting the epithelium from acid and other chemical insults.

• Acid: Hydrochloric acid is the acid which for years we have commonly attributed many problems to within our stomach. This acid is so caustic, that it can dissolve nails. It creates a very acidic environment which allows the activation of many other enzymes needed for digestion. It also inactivates bacteria which may have been swallowed while eating.

• Proteases such as pepsinogen are secreted from the stomach lining, and starts the process of protein digestion (carbohydrates and fats are digested in the intestines). Chymosin (rennin) is also a protease which coagulates milk, allowing it to be retained longer within the stomach for digestion.

• Gastrin is a hormone in your stomach that causes your stomach to produce acid. The acid is used to dissolve and digest foods. Gastrin is also necessary for the normal growth of the stomach lining.

• Ghrelin is a hormone produced in the stomach in the absence of food in the digestive system and stimulates appetite

• Nerve regulators such as acetylcholine which causes acids to be released in the stomach and enhances the force of the stomach contraction, so full is propelled through the stomach to the intestines. Adrenaline, another nerve regulator, relaxes the walls of the stomach.

• Intrinsic factors are also secreted. The best known function of these intrinsic factors are the part they play in enabling vitamin B12 to be absorbed from the intestines.

Now that you are fortified with knowledge of how the stomach works, you are in a better place to understand how things can go wrong, and cause disease. Please see other articles within this web-site for further information about abnormal body processes or causes of gastritis.