KINE 2P20 Lecture Notes - Lecture 2: Pylorus, Ileum, Parietal Cell
9 May 2018
School
Department
Course
Professor
Nutrition 2P20
CHPT 3
Transit Time: amount of time it takes food to pass through the length of the GI tract
Structure/Anatomy of the SI Wall
- 2 Layers of smooth muscle
- 2 Layers of connective tissue
- Lumen: inside of GI tract
- Mucosa: responsible for the absorption of end products of digestion
Digestive Secretions
- Mucus: viscous material produced by goblet cells (mucosal cells); mucus moistens,
lubricates and protects the GI tract
- Enzymes: protein molecules that accelerate the breakdown of specific nutrients
- Hormones: regulate activity of digestive tract. Released into bloodstream
Digestive Enzymes
- Salivary amylase: breaks starch into smaller carb molecules
- Pepsin: breaks proteins into polypeptides and amino acids
- Typsin: breaks proteins and polypeptides into shorter polypeptides
- Chymotrypsin: breaks proteins and polypeptides into shorter polypeptides
- Carboxypeptidase: breaks polypeptides into amino acids
- Pancreatic Lipase: breaks triglycerides into monoglycerides, fatty acids and glycerol
- Pancreatic Amylase: breaks starch into shorter glucose chains, maltose
- Carboxypeptidase, aminopeptidase, and dipepsidase: breaks polypeptides into amino
acids
- Lipase: breaks monoglycerides into fatty acids and glycerol
- Sucrase: breaks sucrose into glucose and fructose
- Lactase: breaks lactose into glucose and galactose
- Maltase: breaks maltose into glucose
Antigen: a foreign substance that stimulates an immune response
Antibodies: secreted by immune cells to fight antigen
Digestion and Absorption
Mouth
- Saliva: moistens food, protects from tooth decay, lubricates upper GI tract
- Salivary Amylase and Lysozymes
- Mastication: chewing
Pharynx, Epiglottis, Esophagus
Stomach
- Grinds and churns bolus of food into semi-liquid chime
- Gastrin triggers release of gastric juices, highly acidic
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Document Summary
Transit time: amount of time it takes food to pass through the length of the gi tract. Mucosa: responsible for the absorption of end products of digestion. Mucus: viscous material produced by goblet cells (mucosal cells); mucus moistens, lubricates and protects the gi tract. Enzymes: protein molecules that accelerate the breakdown of specific nutrients. Salivary amylase: breaks starch into smaller carb molecules. Pepsin: breaks proteins into polypeptides and amino acids. Typsin: breaks proteins and polypeptides into shorter polypeptides. Chymotrypsin: breaks proteins and polypeptides into shorter polypeptides. Pancreatic lipase: breaks triglycerides into monoglycerides, fatty acids and glycerol. Pancreatic amylase: breaks starch into shorter glucose chains, maltose. Carboxypeptidase, aminopeptidase, and dipepsidase: breaks polypeptides into amino acids. Lipase: breaks monoglycerides into fatty acids and glycerol. Sucrase: breaks sucrose into glucose and fructose. Antigen: a foreign substance that stimulates an immune response. Antibodies: secreted by immune cells to fight antigen. Saliva: moistens food, protects from tooth decay, lubricates upper gi tract.
