Digestive System 2 Flashcards
Cephalic phase
This is a reflex that occurs before the food enters the stomach
Caused by seeing thinking tasting or smelling food
Lasts only minutes
Happens in order to prepare digestive system for food. Increased silva production and secretion
What is the second phase of gastric secretion?
Gastric phase
Gastric phase
Lasts 2-3 hours
Stimulated by distension, low acidity, and peptides
Inhibited by excessive acidity in stomach and emotional stress
Gastric phase occurs enhance gastric secretions, acidify chyme , begins protein digestion
Intestinal phase
Third phase of gastric secretion
Lasts for hours
Stimulated by presence of partially digested food in the duodenum or distention of the duodenum when stomach begins to empty
Liver
Creates bile salts which emulsify and breakdown fats; the bile salts are dumped into the duodenum
Also makes bilirubin which helps to colors stool brown gets rid of waste products of the heme of hemoglobin
Gallbladder
Stores bile and concentrates it. Bile is dumped into cystic duct into the bile duct
Pancreas
It makes bicarbonate ions, proteases, lipases, and nucleases.
Neutralizes acidic chyme making ideal environment for enzymes. Proteases digest protein, lipases digest fat, and nucleases digest nucleic acids
All of these substances get dumped into the duodenum
Carbs are digested
In the mouth and small intestine by salivary amylase and pancreatic amylase
Proteins are digested
In the stomach and small intestine by pepsin, pancreatic enzymes; trypsin, chymotrypsin, carboxypeptidase
Fats are digested
In the stomach and small intestine by gastric lipase and emulsification by detergent bile salts from the liver
Nucleic acids are digested
In the small intestine
What is the first phase of gastric secretion?
The cephalic phase
