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42 Cards in this Set
- Front
- Back
What are the components of the dig. system?
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tract
acc. organs: salivary glands liver gallbladder pancreas |
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What are the 6 processes of the digestive system?
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ingestion
mechanical processing digestion secretion absorption excretion |
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What protects the trachea from food?
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Epiglottis
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What is the process of moving a bolus called?
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peristalsis
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What are the 3 layers of muscle in the stomach called?
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longitudinal
circular oblique |
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What are the layers of the stomach wall?
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mucosa (includes gastric pit)
submucosa muscularis externa serosa |
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What are the 3 regions of the small intestine called?
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Duodenum
Jejunum Ileum |
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What purpose does the villi throughout the GI system serve?
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increase surface area
house capillaries and lacteal (lymph capillaries) |
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Where would you find the friendly flora?
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Large intestine: e.g. e.coli
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What are the functions of the large intestine?
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absorption
"bulking up" |
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What are the functions of the liver?
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storage
lipid metabolism carb metabolism |
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What are Kupffer cells?
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hepatic macrophages found in liver sinusoids
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What are the functions of hepatocytes?
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production of bile
processing bloodborne nutrients storage of fat-soluble vitamins detoxification |
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What part of the gallbladder controls bile secretion?
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Sphincter of Oddi
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Insulin and glucagon are released by?
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pancreas
(insulin: beta cells, gulcagon: alpha cells) |
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What does insulin do in the body?
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increases the storage of glucose in the liver, fat and protein
increases cellular uptake of glucose |
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What does glucagon do in the body?
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increases blood glucose levels
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What causes the release of glucagon?
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low blood sugar
high protein meals exercise and stress |
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What is the purpose of digestion?
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To present organic compounds in an accessible form (small molecules that are able to be absorbed)
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What amount of energy do carbs produce?
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16kj/gram
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What do monosaccharides include?
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glucose
fructose galactose |
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What do disaccharides include?
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sucrose
lactose maltose |
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In the mouth, how are carbs digested?
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salivary amylase breaks starch down into smaller molecules
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In the stomach, how are carbs digested?
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They aren't - acidic environment stops salivary amylase but no further digestion occurs
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In the small intestine, how are carbs digested?
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pancreatic amylase is released
intestinal cells release maltase, sucrase and lactase monosaccharides are absorbed |
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What happens to fats in the stomach?
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gastric lipase acts on triglycerides
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What happens to fats in the small intestine?
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most fat digested here
cholecystokinin (CCK) stimulates pancreas to release pancreatic lipase CCK stimulates release of bile to help emulsify fat fat broken down into monoglycerides and fatty acids |
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How is protein digested in the stomach?
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gastrin (hormone) releases pepsinogen from chief cells in stomach
pepsinogen converted to pepsin by acid in stomach pepsin breaks down proteins into peptones |
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How is protein digested in small intestine?
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CCK released
trypsin, chymotrypsin and carboxypeptidase released into duodenum by pancreas these break peptones into peptides and amino acids can now be absorbed |
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What is absorbed in the stomach?
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water
some alcohol some forms of fats |
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What is absorbed in the small intestine?
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Nearly everything
95% of ingested energy from protein, fat, carbs and alcohol |
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What is absorbed in large intestine?
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water, minerals, short-chain fatty acids
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Where does the enterohepatic circulation run?
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liver - gallbladder - small intestine - portal vein - liver
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What is metabolism?
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sum of all body activities
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How is energy stored in the body?
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adenosine triphosphate (ATP)
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What are the 3 metabolic processes to produce energy?
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aerobic
anaerobic/glycolysis ATP-CP |
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How does the ATP-CP system work?
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Creatine phosphate and ATP stored, broken down and energy released
only 3-15 seconds of maximal effort |
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How does the anaerobic/lactic acid system work?
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breakdown of glucose to lactic acid (no oxygen required)
rise in acidity triggers muscle fatigue 30 sec - 2 mins of intense activity =2 ATP |
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How does the aerobic system work?
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breakdown of fat and carbs for energy
pyruvate --> acetyl CoA --> citric acid cycle (Krebs cycle) 2min - 3 hrs yields 34 ATP per cycle |
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What is catabolism?
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breaking down
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What is anabolism?
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building up
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How much food (chemical energy) is stored as ATP?
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40%
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