G Cells

Definition

G cells, also known as gastrin-producing cells, are a type of endocrine cell found primarily in the pyloric antrum of the stomach. These cells are responsible for the production and secretion of the hormone gastrin, which plays a crucial role in the digestive process and the regulation of stomach acid secretion.

5 Must Know Facts For Your Next Test

1. G cells are responsible for the production and secretion of the hormone gastrin, which is a key regulator of gastric acid secretion.
2. Gastrin stimulates the parietal cells in the stomach to secrete hydrochloric acid (HCl), which creates the acidic environment necessary for the digestion of food.
3. The pyloric antrum, the distal portion of the stomach, is the primary location where G cells are found.
4. The release of gastrin from G cells is triggered by the presence of certain amino acids, peptides, and distension of the stomach wall during the digestive process.
5. Abnormalities in G cell function, such as excessive gastrin production, can lead to conditions like Zollinger-Ellison syndrome, which is characterized by severe peptic ulcers.

Review Questions

• Explain the role of G cells in the regulation of stomach acid secretion.
  • G cells, located primarily in the pyloric antrum of the stomach, are responsible for the production and secretion of the hormone gastrin. Gastrin stimulates the parietal cells in the stomach to secrete hydrochloric acid (HCl), which creates the acidic environment necessary for the digestion of food. The release of gastrin from G cells is triggered by the presence of certain amino acids, peptides, and distension of the stomach wall during the digestive process. This regulatory mechanism ensures that the appropriate amount of stomach acid is produced to facilitate the breakdown and absorption of nutrients.
• Describe the relationship between G cells, parietal cells, and the digestive process.
  • G cells, parietal cells, and the digestive process are intimately connected. G cells produce and secrete the hormone gastrin, which acts on parietal cells to stimulate the secretion of hydrochloric acid (HCl). The acidic environment created by the HCl secretion is essential for the activation of pepsin, an enzyme that breaks down proteins, and for the overall digestion of food. The release of gastrin from G cells is triggered by the presence of certain nutrients and the distension of the stomach wall during the digestive process, ensuring that the appropriate amount of stomach acid is produced to facilitate the breakdown and absorption of nutrients.
• Analyze the potential consequences of abnormalities in G cell function and their impact on the digestive system.
  • Abnormalities in G cell function, such as excessive gastrin production, can lead to serious digestive issues. One example is Zollinger-Ellison syndrome, a condition characterized by severe peptic ulcers. In this disorder, the excessive production of gastrin by G cells results in the overproduction of stomach acid, which can damage the lining of the stomach and duodenum, leading to the formation of painful ulcers. This disruption in the normal regulation of stomach acid secretion can also have broader implications, such as impaired nutrient absorption and an increased risk of complications like bleeding or perforation of the digestive tract. Understanding the critical role of G cells in the digestive process is essential for identifying and managing such conditions effectively.

Related terms

Gastrin: Gastrin is a peptide hormone produced by G cells in the stomach that stimulates the secretion of gastric acid (hydrochloric acid) by parietal cells, which is essential for the digestion of food.

Parietal Cells: Parietal cells are the cells in the stomach lining that secrete hydrochloric acid (HCl), which creates the acidic environment necessary for the digestion of food and the activation of pepsin, an enzyme that breaks down proteins.

Pyloric Antrum: The pyloric antrum is the distal portion of the stomach, located between the body of the stomach and the pylorus (the opening of the stomach into the duodenum). It is the primary site where G cells are found.