How the Stomach Protects Itself from Acid: Mucus and Bicarbonate

The stomach's gastric juices are highly acidic and can have a pH of as low as 1.5. This acidity is necessary for breaking down food and killing harmful bacteria. However, the stomach lining must be protected from the corrosive effects of these juices. This is done by a layer of mucus that coats the stomach lining. The mucus is produced by specialized cells in the stomach lining called mucous cells.

In addition to mucus, the stomach also produces bicarbonate ions (HCO3-). These ions help to neutralize the gastric juices and raise the pH of the stomach contents. Bicarbonate ions are produced by the parietal cells in the stomach lining.

The combination of mucus and bicarbonate ions creates a protective barrier that prevents the stomach lining from being damaged by the gastric juices. This barrier is essential for maintaining the health of the stomach and for allowing it to function properly.