Flashcards in Digestive/Endocrine Deck (68)
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1
Liver Role in Digestion
Secretion of bile
2
Hepatic Triad
Hepatic Portal Vein
Bile Duct
Hepatic Artery
3
Hepatic Portal Vein
70% of blood that goes through the liver
4
Bile Duct
Collection of bile from all cells
5
Hepatic Artery
30% of blood that goes through the liver
6
Gallbladder
Stores bile produced in the liver and concentrates it
7
Pathway of Bile Secretion
1. Bile capillaries
2. Hepatic ducts create common hepatic duct
3. Cystic duct (gallbladder) and common hepatic duct make common bile duct
4. Common bile duct and pancreatic duct empty into duodenum
8
Components of Bile
1. Water and cholesterol
2. Bile salts (Na and K)
3. Bile pigments (bilirubin) from hemoglobin molecule
9
Acini
Dark clusters in the pancreas
Exocrine
99% of pancreas
Produce pancreatic juice
10
Islets of Langerhans
1% of gland
Pale staining cells
Produce hormones
11
Pancreatic Juice Components
Water, enzymes, and sodium bicarbonate
12
Digestive Enzymes of Pancreas
Pancreatic amylase
Pancreatic lipase
Ribonuclease
Deoxyribonuclease
Zymogens
13
Zymogens of Pancreas
Trypsinogen
Chymotrypsinogen
Procarboxypeptidase
14
Activation of Zymogens
Trypsinogen converted to trypsin by intestinal epithelium
Trypsin converts other two zymogens as well as digests dietary protein
15
Regulation of Pancreatic Secretions
Acetylcholine
Secretin
Cholecystokinin
16
Acetylcholine in Pancreas
Vagal origin
Stimulates acini to secrete enzymes during cephalic phase
17
Secretin in Pancreas
Acidity in intestine causes increased sodium bicarbonate release
18
Cholecystokinin in Pancreas
Fats and proteins cause increased digestive enzyme release, contraction of gallbladder, and relaxation of Sphincter of Oddi
19
Equations for Regulation of Pancreatic Secretions
HCl + NaHCO3 --> NaCl + H2CO3 --> NaCl + H2O + CO2
H2O goes into stomach, CO2 goes into the blood
Decreases acidity, lowers pH
20
Anatomy of Small Intestine
Duodenum
Jejunum
Ileum
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Where does all absorption occur?
Small intestine
22
Histology of Small Intestine
1. Circular Folds (increase surface area, slow progress of chyme)
2. Gastric Pits (secrete chemicals)
3. Villi (contains arteriole, blood capillaries, venule, and lymphatic capillary)
4. Microvilli (contain enzymes that complete chemical digestion; contain brush border enzymes)
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Functions of Microvilli
Absorption and digestion
Significant cell division within intestinal glands
Rupture and release digestive enzymes and proteins
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Cells of Intestinal Glands
1. Microvilli
2. Goblet Cell
3. Enteroendocrine Cell
4. Paneth Cell
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Enteroendocrine Cell
Secretes secretin, CCK, or gastric inhibitory peptide
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Paneth Cell
Secretes lysozyme
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Segmentation
Local mixing of chyme with intestinal juices
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Digestion of Carbohydrates
1. Mouth: salivary amylase
2. Esophagus and Stomach: nothing
3. Duodenum: pancreatic amylase
4. Brush border enzymes (maltase, sucrase, and lactase) act on disaccharides to produce monosaccharides
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Digestion of Proteins
1. Stomach: HCl denatures proteins and pepsin turns into peptides
2. Pancreas: trypsin and chymotrypsin take over
3. Carboxypeptidase: removes AA from carboxyl group
4. Aminopeptidase: removes AA from nitrogenous group
5. Dipeptidase: splits dipeptides in the middle and releases the last two free AA
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