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Why are chlorides present in gastric hydrochloric acid?

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A labeled diagram of the chlorine element from the periodic table shows its atomic number 17, symbol Cl, electron configuration, and atomic weight range. The box is shaded green to indicate chlorine is a halogen, with icons for orthorhombic crystal structure, gas state at room temperature, and strong acidity. A key explains the icons and colors used. — chlorine Properties of chlorine.

Chlorides are present in gastric hydrochloric acid because they are essential components of the body's digestive secretions. Within the stomach, specialized cells known as parietal cells secrete hydrogen ions that combine with chloride ions to form hydrochloric acid.12

This process is a vital physiological function, as hydrochloric acid plays a key role in the digestive process. Beyond their role in gastric acid, chlorides are crucial for maintaining electrical neutrality, regulating pressure in extracellular fluids, and supporting the body's acid-base balance. Because chlorine is a component of all body secretions and excretions, the body relies on the intake of sodium chloride to maintain these necessary levels.31