Digestive System Flashcards
What are the 6 Classes of Nutrients?
- Carbohydrates
- Protein
- Fat
- Vitamins
- Minerals
- Water
What are the 2 primary functions of the digestive system?
Digestion (breakdown of nutrients)
Absorption (movement of nutrients from intestinal tract into circulation.
What structures make up the Upper GI Tract?
- Oral Cavity (Mouth & Pharynx)
- Esophagus (Lower Esophageal Sphincter)
- Stomach (Plyoric Sphincter)
What structures make up the Lower GI Tract?
- Small Intestine (Duodenum, Jejunum, Ileum)
- Large Intestine (Cecum, Ascending, Descending, Transverse, Sigmoid)
- Rectum
- Intestinal Microstructure
What are some components of the Intestinal Microstructure?
Microvili
Enterocytes
Brush Boarder
What components make up the Small Intestine?
Duodenum, Jejunum, Ileum
What components make up the Large Intestine?
Cecum, Ascending Colon, Descending Colon, Transverse Colon, Sigmoid Colon, Rectum
What are 3 accessory organs to the Digestive Tract
Liver, Gallbladder, Pancreas
What is the Liver responsible for as it relates to the GI Tract?
Produces bile, an important secretion needed for lipid digestion.
What is the Gallbladder responsible for as it relates to the GI Tract?
Stores and releases bile, needed for lipid digestion.
What is the Pancreas responsible for as it relates to the GI Tract?
Releases pancreatic juice that neutralizes chyme and contains enzymes needed for carbohydrate, protein, and lipid digestion.
What enzymes (produced in the oral cavity) are associated with digestion.
Salivary Amylase (carbs)
Lingual Lipase (lipids)
How does the LES regulate food entry into the stomach?
Pressure drops to allow food passage
(regulated by neural and hormonal mechanisms)
In the stomach, Gastric Juices are composed of what?
- Water
- Electrolytes
- Bicarbonate
- Mucas
- HCI (protein denaturation & kills bacteria)
- Enzymes (Pepsinogen, Denatured Salivary Amylase, Gastic Lipase)
- Intrinsic Factor
What is the standard emptying rates for the stomach for liquids and solids?
Liquids (fast) 1-2 hours
Solids (slow) 2-3 hours
Where do secretions from the pancreas make their way into the small intestine through?
Duodenum
Where does Salivary Amylase secrete from & act at?
Secrets from the Mouth, acts in the Mouth.
Where does Lingual Lipase secrete from & act at?
Secrets from the Mouth, acts in the Stomach & small intestine.
Where does Pepsinogen / Pepsin secrete from & act at?
Secrets from the Stomach, acts in the Stomach.
Where does Gastric Lipase secrete from & act at?
Secrets from the Stomach, acts in the Stomach
Where does Trypsinogen / Trypsin secrete from & act at?
Secrets from the Pancreas, acts in the Small Intestine
Where does Chymotrypsinogen / Chymotrypsin secrete from & act at?
Secrets from the Pancreas, acts in the Small Intestine.
Where does Procarboxypeptidase / Caboxypeptidase A secrete from & act at?
Secrets from the Pancreas, acts in the Small Intestine.
Where does Caboxypeptidase B secrete from & act at?
Secrets from Pancreas, acts in the Small Intestine.
Where does Pancreatic a amylase secrete from & act at?
Secrets from Pancreas, acts in the Small Intestine.
Where does Pancreatic Lipase & Colipase secrete from & act at?
Secrets from Pancreas, acts in the Small Intestine.
Where does Phospholipase secrete from & act at?
Secrets from Pancreas, acts in the Small Intestine.
Where does Cholesterol Esterase secrete from & act at?
Secrets from Pancreas, acts in the Small Intestine.
Where does Amino Peptidases secrete from & act at?
Secrets from Small Intestine, acts in the Small Intestine.
Where does Dipeptidases secrete from & act at?
Secrets from Small Intestine, acts in the Small Intestine.
Where does Alpha Dextrinase (or) Isomaltase secrete from & act at?
Secrets from Small Intestine, acts in the Small Intestine.
Where does Disaccharidases (sucrase, maltase, lactase) secrete from & act at?
Secrets from Small Intestine, acts in the Small Intestine.
Bile Acids are synthesized from where?
Synthesized from Cholesterol in the Liver
What is the difference between probiotics, and prebiotics?
Probiotics contain LIVE bacterial cultures, whereas prebiotics are food ingredients that promote bacterial growth.
What are the 2 routes of absorption of nutrients?
Either through the bloodstream or lymphatic system.
Absorption through the bloodstream involves primarily _____ ?
Water Soluble nutrients (through portal circulation: liver)
Absorption through the lymphatic system involves primarily _____ ?
Fat Soluble nutrients (through subclavian vein: vena cava)
- heart delivers nutrients to general circulation.
Approximately how efficient are we at absorbing CHO?
98%
Approximately how efficient are we at absorbing Protein?
92%
Approximately how efficient are we at absorbing Fat?
95%
