Gastrin

Definition

Gastrin is a hormone produced by G cells in the stomach that stimulates the secretion of gastric acid. This hormone plays a crucial role in regulating digestive processes, particularly in promoting gastric motility and acid production to facilitate food breakdown and digestion.

5 Must Know Facts For Your Next Test

1. Gastrin is released into the bloodstream in response to food entering the stomach, especially proteins.
2. The main function of gastrin is to stimulate parietal cells to secrete hydrochloric acid, which aids in breaking down food.
3. Gastrin levels can be influenced by factors such as pH levels in the stomach and the presence of certain nutrients.
4. An overproduction of gastrin can lead to conditions like Zollinger-Ellison syndrome, characterized by excessive gastric acid secretion and ulcers.
5. Gastrin not only promotes acid secretion but also enhances gastric motility, ensuring that food is mixed adequately for digestion.

Review Questions

• How does gastrin contribute to the process of digestion in the stomach?
  • Gastrin contributes to digestion by stimulating G cells to secrete hydrochloric acid from parietal cells, which is crucial for breaking down proteins and activating digestive enzymes. It also increases gastric motility, helping to mix food with digestive juices. This coordinated action ensures efficient digestion and nutrient absorption, demonstrating gastrin's essential role in the digestive process.
• Discuss how gastrin levels are regulated and what factors can influence its secretion.
  • Gastrin levels are regulated by several factors, including the presence of food, particularly protein, in the stomach. When food enters the stomach, G cells are stimulated to release gastrin into the bloodstream. Additionally, low pH levels in the stomach can trigger gastrin secretion as a mechanism to increase acidity for digestion. Conversely, when pH rises or food leaves the stomach, gastrin release decreases to prevent excessive acid production.
• Evaluate the potential clinical implications of abnormal gastrin levels and their impact on gastrointestinal health.
  • Abnormal gastrin levels can have significant clinical implications. An overproduction of gastrin may lead to conditions like Zollinger-Ellison syndrome, resulting in recurrent ulcers and severe gastrointestinal discomfort due to excessive gastric acid. On the other hand, low gastrin levels could impair digestion and lead to malabsorption issues. Understanding these abnormalities is vital for diagnosing gastrointestinal disorders and tailoring appropriate treatment plans.

Related terms

G cells: Specialized cells in the stomach lining that produce gastrin in response to food intake.

HCl (hydrochloric acid): A strong acid secreted by parietal cells in the stomach, essential for digestion and activated by gastrin.

Enterogastrone: A hormone that inhibits gastric secretion and motility, acting as a counterbalance to gastrin in regulating digestion.