NBEO General Physiology Practice Exam

The primary cell type responsible for the secretion of digestive enzymes in the stomach is the chief cell. Chief cells are specialized cells located in the gastric glands of the stomach lining, and their main function is to produce and secrete pepsinogen, which is the inactive precursor of the enzyme pepsin. Pepsin plays a critical role in the digestion of proteins by breaking them down into smaller peptides.

In addition to pepsinogen, chief cells may also secrete gastric lipase, an enzyme that aids in the digestion of fats. The activation of pepsinogen to pepsin occurs in the acidic environment of the stomach, primarily facilitated by hydrochloric acid, which is secreted by parietal cells.

Other cell types mentioned in the question serve different roles in gastric physiology. Parietal cells are crucial for producing hydrochloric acid, which helps create an acidic environment for enzyme activity and aids in the absorption of certain nutrients. G cells are involved in the secretion of the hormone gastrin, which stimulates gastric acid secretion and promotes digestive processes. Endocrine cells in the stomach can release various hormones that regulate digestive function but are not directly involved in the secretion of digestive enzymes.

Thus, the correct identification of chief cells highlights their