Control of digestive processes
Hormone Regulators
A fascinating feature of the digestive system is that it contains its own regulators. The major hormones that control the functions of the digestive system are produced and released by cells in the mucosa of the stomach and small intestine. These hormones are released into the blood of the digestive tract, travel back to the heart and through the arteries, and return to the digestive system, where they stimulate digestive juices and cause organ movement. The hormones that control digestion are gastrin, secretin, and cholecystokinin (CCK):
Nerve Regulators
Two types of nerves help to control the action of the digestive system. Extrinsic (outside) nerves come to the digestive organs from the unconscious part of the brain or from the spinal cord. They release a chemical called acetylcholine and another called adrenaline. Acetylcholine causes the muscle of the digestive organs to squeeze with more force and increase the "push" of food and juice through the digestive tract. Acetylcholine also causes the stomach and pancreas to produce more digestive juice. Adrenaline relaxes the muscle of the stomach and intestine and decreases the flow of blood to these organs.
Even more important, though, are the intrinsic (inside) nerves, which make up a very dense network embedded in the walls of the esophagus, stomach, small intestine, and colon. The intrinsic nerves are triggered to act when the walls of the hollow organs are stretched by food. They release many different substances that speed up or delay the movement of food and the production of juices by the digestive organs.
Related Topics:
1. Your Digestive System and How it Works. National Digestive Diseases Information Clearinghouse (NDDIC). National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). National Institutes of Health NIH Publication No. 04–2681 May 2004. http://digestive.niddk.nih.gov/ddiseases/pubs/yrdd/index.htm
2. Digestive Diseases A-Z. National Digestive Diseases Information Clearinghouse (NDDIC). National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).National Institutes of Health. NIH Publication No. 00–2750 February 2000
Page Last Revised: August 26, 2011
Hormone Regulators
A fascinating feature of the digestive system is that it contains its own regulators. The major hormones that control the functions of the digestive system are produced and released by cells in the mucosa of the stomach and small intestine. These hormones are released into the blood of the digestive tract, travel back to the heart and through the arteries, and return to the digestive system, where they stimulate digestive juices and cause organ movement. The hormones that control digestion are gastrin, secretin, and cholecystokinin (CCK):
Gastrin causes the stomach to produce an acid for dissolving and digesting some foods. It is also necessary for the normal growth of the lining of the stomach, small intestine, and colon.Additional hormones in the digestive system regulate appetite:
Secretin causes the pancreas to send out a digestive juice that is rich in bicarbonate. It stimulates the stomach to produce pepsin, an enzyme that digests protein, and it also stimulates the liver to produce bile.
CCK causes the pancreas to grow and to produce the enzymes of pancreatic juice, and it causes the gallbladder to empty.
Ghrelin is produced in the stomach and upper intestine in the absence of food in the digestive system and stimulates appetite.Both of these hormones work on the brain to help regulate the intake of food for energy.
Peptide YY is produced in the GI tract in response to a meal in the system and inhibits appetite.
Nerve Regulators
Two types of nerves help to control the action of the digestive system. Extrinsic (outside) nerves come to the digestive organs from the unconscious part of the brain or from the spinal cord. They release a chemical called acetylcholine and another called adrenaline. Acetylcholine causes the muscle of the digestive organs to squeeze with more force and increase the "push" of food and juice through the digestive tract. Acetylcholine also causes the stomach and pancreas to produce more digestive juice. Adrenaline relaxes the muscle of the stomach and intestine and decreases the flow of blood to these organs.
Even more important, though, are the intrinsic (inside) nerves, which make up a very dense network embedded in the walls of the esophagus, stomach, small intestine, and colon. The intrinsic nerves are triggered to act when the walls of the hollow organs are stretched by food. They release many different substances that speed up or delay the movement of food and the production of juices by the digestive organs.
Related Topics:
1. Digestive System: Anatomy and Physiology of the Digestive SystemSources:
2. Production of Digestive Juices
3. Absorption and Transport of Nutrients
4. How is the digestive process controlled? (Current Page)
1. Your Digestive System and How it Works. National Digestive Diseases Information Clearinghouse (NDDIC). National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). National Institutes of Health NIH Publication No. 04–2681 May 2004. http://digestive.niddk.nih.gov/ddiseases/pubs/yrdd/index.htm
2. Digestive Diseases A-Z. National Digestive Diseases Information Clearinghouse (NDDIC). National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).National Institutes of Health. NIH Publication No. 00–2750 February 2000
Page Last Revised: August 26, 2011
