Ch:21 Digestive System Flashcards
What type of cells are important in secretion and absorption in the digestive system?
Epithelial cells
What do secretions in the digestive system include?
Digestive enzymes, stomach acid, base to neutralize acid, and waste products.
What are the three phases of digestion?
- Cephalic phase (Mouth and esophagus)
- Gastric phase (Stomach)
- Intestinal phase (Small intestine)
What stimulates the cephalic phase?
- The anticipation of food
2. Food in the mouth
What 2 digestive enzymes are in saliva?
What are their functions?
Amylase- Breaks down starch
Lysozyme- Attacks bacteria
What are the 3 functions of the stomach?
- Storage
- Digestion
- Protection against bacteria & other pathogens
What does the stomach secrete?
- HCl (parietal cells)
- Pepsinogen & Gastric lipase (chief cells)
- Mucus & Bicarbonate (surface mucous cells)
- Gastrin (G cells)
- Histamine (ECL cells)
What is digested in the stomach?
Mainly proteins but also minimal fats
What is absorbed in the stomach?
Lipid-soluble substances such as alcohol and aspirin
What type of motility is used in the stomach?
Peristaltic mixing & propulsion
What is digested in the mouth?
Carbohydrates
What is absorbed in the mouth?
Nothing
What type of motility is used in the mouth?
Chewing & Swallowing
What is secreted into the small intestine?
- Enzymes (enterocytes)
- Mucus (globlet cells)
- Hormones (CCK, secretin, GIP)
- Enzymes and Bicarbonate (exocrine pancreas)
- Bile (liver, stored in gallbladder)
What is digested in the small intestine?
Polypeptides, carbs, fats & nucleic acids
What is absorbed in the small intestine?
-Amino Acids & small peptides
-Monosaccharides, Fatty acids, monoglycerides,
& cholesterol
-Nitrogenous bases, water, ions, minerals & vitamins
What type of motility is used in the small intestine?
Mixing & propulsion primarily by sedimentation
and some peristalsis
The small intestine receives secretions from the ______ & ________.
Liver & Pancreas
What does the liver secrete to the small intestine?
Bile
What does the pancreas secrete to the small intestine?
Bicarbonate to neutralize stomach acid
What is secreted into the Large intestine?
Mucus (goblet cells)
What is digested in the Large intestine?
Nothing (except by bacteria)
What is absorbed in the Large intestine?
ions, minerals, vitamins, water and small organic molecules made by gut bacteria
What type of motility is used in the Large intestine?
Segmental mixing & mass movement for propulsion