Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

At what pH range is gastric acid maintained?

1. 7-8

2. 4-5

3. 1-3

4. 0-1

The correct answer is: 1-3

Gastric acid, primarily composed of hydrochloric acid, is maintained within a pH range of approximately 1 to 3. This highly acidic environment is essential for several important functions in the digestive process. It facilitates the breakdown of food, activates digestive enzymes such as pepsin, and provides a barrier against pathogens that may enter the stomach with ingested food. The extremely low pH is achieved through the secretion of hydrogen ions by parietal cells in the stomach lining. This acidic condition not only aids in digestion but also serves to denature proteins, making it easier for enzymes to further break them down. Other pH ranges provided in the options do not accurately reflect the true acidic environment of gastric acid. For instance, a pH of 7-8 is considered neutral and would not support the required acidity for digestion, while 4-5 indicates a much less acidic environment that would impair the digestive processes. Similarly, a pH of 0-1 would be too extreme, as it does not accurately represent the normal variation typically found in gastric fluid. Therefore, maintaining a pH around 1 to 3 is crucial for optimal gastric function.