The gastric glands, located in the stomach lining, secrete gastric juice.
Understanding Gastric Glands and Gastric Juice
Gastric glands are branched tubules found within the stomach's inner lining. These glands are not a single entity but rather a complex system of specialized cells working together to produce gastric juice. This juice is a crucial component of digestion, containing several key substances:
- Hydrochloric acid (HCl): Produced by parietal cells, HCl creates the highly acidic environment necessary for pepsin activity and killing ingested bacteria. [Source: Britannica, NCBI Bookshelf, UpToDate]
- Pepsinogen: Chief cells secrete pepsinogen, an inactive precursor to pepsin. When exposed to the acidic environment created by HCl, pepsinogen converts to pepsin. [Source: Britannica, NCBI Bookshelf, Byjus]
- Mucus: Mucous cells produce mucus which protects the stomach lining from the corrosive effects of HCl and pepsin. [Source: Britannica, Lumen Learning]
- Gastrin: G cells, primarily located in the pyloric glands (a type of gastric gland), secrete the hormone gastrin, stimulating further gastric acid secretion. [Source: Wikipedia, ScienceDirect, UpToDate]
- Intrinsic factor: This is crucial for vitamin B12 absorption. [Source: Not explicitly stated in references, but a known component of gastric juice.]
The secretion of gastric juice is stimulated by both chemical signals from food and the stretching of the stomach walls as food enters. [Source: ScienceDirect]
The precise composition of gastric juice can vary depending on factors such as the type of food ingested and the individual's health.
Different Types of Gastric Glands
It's important to note that not all gastric glands secrete the same components in the same proportions. For example, pyloric glands, located in the antrum of the stomach, contain fewer parietal cells and secrete more gastrin than oxyntic glands (also known as gastric glands) located in the body and fundus of the stomach. [Source: Wikipedia, UpToDate]
