Accessory Organs, Enzymes and Hormones Flashcards
Define Enzymes
Enzymes are proteins that speed up chemical reactions with less energy
Amylase
- carbohydrate-digesting enzyme found within the mouth’s saliva
- Breaks down starch into disaccharides (smaller chains of carbohydrates)
Pepsin
Pepsinogen is released into the stomach cavity where it reacts with HCl and is converted into pepsin (active enzyme form)
Pepsin digests proteins in the stomach
Pancreas enzymes
Protein digesting enzyme: trypsin
Fat digesting enzyme: lipase
Carbohydrate digesting enzyme: pancreatic amylase
Define Hormones
GI hormones are chemical messengers that [control] physiological functions of the GI tract: secretion, absorption & digestion & gut motility.
Gastrin
- stimulates release of HCl and pepsinogen from the stomach lining
- produced by the stomach
Ulcers
Mucus protects the lining of the stomach from the pepsin and HCl
When the mucus layer breaks down, the lining of the stomach is exposed and peptic ulcers develop
Secretin
When acidic chyme enters the small intestine, the hormone secretin is activated and released from the epithelial cells that line small intestine
- stimulates liver to secrete bile
- encourages pancreas to neutralize acidic chyme from the stomach (raise the pH)
CCK
- When fat-rich chyme is in the small intestine, cck is released
- causes pancreas to release digestive enzymes AND the gallbladder to release bile
Liver
- detoxifies harmful substances in the blood
- breaks down old red blood cells
- stores substances such as vitamins and glycogen (form of carbohydrate)
- Produces Bile (contains bile salts)
Gallbladder
- Stores bile
- The bile is released by CCK
Pancreas
- Pancreatic secretions protect the lining of the small intestine from the gastric juices of the stomach
- Neutralizes secretion
