What are the hormones secreted from small intestine during digestion process?

During the process of digestion, the small intestine secretes several hormones that play important roles in regulating the digestion and absorption of nutrients. These hormones are produced by specialized cells in the intestinal mucosa and released into the bloodstream, where they can travel to target organs and tissues to exert their effects.

Here are some of the key hormones secreted from the small intestine during digestion:

1. Gastrin: Gastrin is produced by G cells in the stomach and upper part of the small intestine. It stimulates the secretion of gastric acid and pepsin from the stomach, which are necessary for the initial digestion of food.

2. Cholecystokinin (CCK): CCK is produced by I cells in the duodenum and jejunum. It stimulates the contraction of the gallbladder, leading to the release of bile into the small intestine. Bile helps in the emulsification and digestion of fats. CCK also inhibits gastric emptying and stimulates the secretion of pancreatic enzymes, including lipases and proteases, which further break down fats and proteins in the small intestine.

3. Secretin: Secretin is produced by S cells in the duodenum and jejunum. It stimulates the secretion of bicarbonate-rich fluids from the pancreas and liver into the small intestine. Bicarbonate helps to neutralize the acidic chyme coming from the stomach and creates a more alkaline environment that is optimal for the activity of pancreatic enzymes.

4. Glucagon-like peptide-1 (GLP-1): GLP-1 is produced by L cells in the ileum and colon. It has multiple effects, including slowing gastric emptying, promoting insulin secretion, suppressing appetite, and inhibiting glucagon secretion. These actions contribute to the regulation of blood glucose levels and energy metabolism.

5. Peptide YY (PYY): PYY is produced by L cells in the ileum and colon. It has anorexigenic effects and can reduce food intake by signaling satiety to the brain. PYY also slows down intestinal transit time, allowing for better nutrient absorption.

These hormones work in a coordinated manner to regulate various aspects of digestion, including the secretion of digestive enzymes, bile, and bicarbonate, as well as the control of gastric emptying and intestinal motility. They help ensure that nutrients are efficiently broken down and absorbed, while also preventing any harmful effects on the intestinal mucosa.