Hormones of the digestive system.ppt
- 1. Hormones of the Digestive System
- 2. Hormone Basics Hormones are secreted into the blood stream and must circulate the body before reaching target location Hormones turn things on (stimulate) or off (inhibit) Hormones are regulated by hypothalamus in the brain Endocrine glands are gland that secrete hormones
- 4. GASTRIN: Secretion: By “G cells” of stomach lining Stimulus: Stomach distention and acid pH of chyme causes gastrin to be produced. Action: 1. increases HCl production in stomach 2. increases gastric motility 3. stimulates growth of gastric mucosa 4. contract lower esophageal sphincter 5. relaxes pyloric sphincter 6. relaxes ileocecal sphincter
- 6. SECRETIN: Secretion: By (S) cells in the small intestine. Stimulus: Acid chyme in small intestine causes secretion of secretin Actions: stimulate secretion of pancreatic juice and bile that is rich in bicarbonate ions. inhibit production of HCl in stomach promote growth and maintenance of the pancreas enhance effects of Cholecystokinin (CCK) Increases rate of bile secretion by liver
- 8. CHOLECYSTOKININ (CCK): Secretion: Enteroendocrine cells in the small intestine mucosa (Crypts of Lieberkuhn) Stimulus: Chyme rich in amino acids, triglycerides and fatty acids enter the small intestine. Actions: increases secretion of pancreatic juice rich in digestive enzymes opens the Sphincter of Oddi (from common bile duct) contracts the gallbladder Inhibits gastric secretion and motility May reduce hunger
- 10. Gastric Inhibitory Peptide (GIP): Secretion: Enteroendocrine cells in the small intestine Stimulus: Chyme rich in glucose enter the small intestine. Actions: Stimulates release of insulin by beta cells of pancreas Inhibits gastric secretion and motility Stimulates glucose use by skeletal muscle cells
- 12. Hormonal control in the Digestive system Pancreas and Islets of Langerhans Endocrine cells make up 1% of the pancreas and are observed as Islets of Langerhans: 1. Alpha Cells: Secrete Glucagon (increases blood sugar) 2. Beta Cells: Secrete Insulin (decreases blood sugar) 3. Delta Cells: Secrete Human Growth Hormone- Inhibiting Hormone (inhibit secretion of both glucagon and insulin and slows rate of nutrient absorption) 4. F-Cells: Secrete Pancreatic Polypeptide (inhibit secretion of digestive enzymes and inhibits contraction of the gallbladder)
- 16. Hunger Hormones Hunger – a feeling of discomfort or weakness caused by a lack of food Satiety – a feeling of fullness
- 18. Hunger Hormones
- 19. Hunger Hormones Case Study Work as a table team to answer the questions in the case study What are some of the issues that are occurring in his body? How might his digestive organs be involved?
- 20. Case Study What is the difference between type 1 and type 2 diabetes?