Term
| anatomy of small intestine |
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Definition
| begins at stomach and ends at large intestine. About 10 ft long when your alive 21 ft when your dead. |
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Term
| 3 regions of sm intestine |
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Definition
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Term
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Definition
· shortest ~10 inches long (12 finger lengths is where it got its name. |
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Definition
| about 3 ft long ( means empty) |
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Definition
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Term
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Definition
mucosa
submucosa
muscularis
serosa |
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Term
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Definition
| simple columnar cells in the shape of villi (finger like projections) |
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Term
| cells in mucosa layer of sm intestine |
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Definition
- absorptive cells
- goblet cells
- enteroendocrine cells
- paneth cells
- lamina propria
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Term
| absorptive cells in sm intestine |
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Definition
| absorb nutrients from chyme |
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Term
| goblet cells of sm intestine |
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Definition
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Term
| enteroendocrine cells of sm intestine |
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Definition
o secretes secretin and cholecystokinin(CCK) |
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Term
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Definition
| secrtes bicarbonate ions to adjust ph |
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Term
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Definition
| hormone that stimulates bile secretion |
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Term
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Definition
| they are protectant cells. secrete lysozymes that kill bacteria & are capable of phagocytosis. |
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Term
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Definition
o contains MALT they are first line of defense for immunes system. |
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Term
| circular folds of sm intestine |
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Definition
| function is to increase absorption of food. They are a group of villi |
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Term
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Definition
| finger like projections. when food comes along it hits one of the absorptive cells and diffuses into the cell |
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Term
| microvilli of sm intestine |
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Definition
| make up the brush boarder |
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Term
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Definition
| 1-2 liters a day, clear yellow fluid made of water and mucus. Slightly alkaline, it aids in the absorption of substances from chyme. |
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Term
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Definition
| localized mixing contractions that occur in area of the intestine that are distended by large amounts of chyme. This process mixes the chyme with digestive juices and brings food particles in contact with the absorptive cells. This process is like squeezing a tube of toothpaste from both ends. Occurs about 12 times a minute in the duodenum. 8 times a minute in the ilium. |
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Term
| migratory motility complex (MMC) |
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Definition
| peristalsis pushes chyme from the stomach to the lg intestine and it usually 90 -120 min for the next movement to begin. |
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Term
| Chemcial digestion in small intestine |
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Definition
· chyme in the small intestine contain partially digested carbs, starch, and lipids. Complete digestion is the goal of intestinal juice, bile, and pancreatic juice. |
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Term
| digestion of charbohydrates in sm intestine |
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Definition
needs to be in the monsacaride form to be absorbed by the cells. enzymes involved:
- pancreatic amylase
- alpha dextronase
- sucrase
- lactase
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Term
| pancreatic amylase in digestion of carbs in sm intestine |
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Definition
| enzyme in pancreatic juice that breaks down glycogen and starches. |
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Term
| alpha dextronase in digestion of carbs in sm intestine |
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Definition
| is a brush boarder(hair like structures) enzyme that clips of glucose one unit at a time. |
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Term
| sucrase in digestion of carbs in sm intestine |
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Definition
| breaks sucrose(table sugar) to glucose and fructose |
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Term
| lactase in carb digestion in sm intestine |
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Definition
| breaks down lactose to glucose and galactose |
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Term
| digestion of protiens in sm intestine |
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Definition
| break polypeptides down to amino acids |
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Term
| enyzymes in protien digestion in sm intestine |
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Definition
cut off polypetides one at a time
- tripsen
- chymostrin
- elastase
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Term
| digestion of lipids in sm intestine |
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Definition
| most lipid digestion occurs in the sm intestine by pancreatic lipase. Bile salts break lg lipids into smaller lipids. Lipids need to be in fatty acid form to be absorbed. |
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Term
| digestion of nucleic acids in sm intestine |
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Definition
pancreatic juice contains ribonuclease and deoxyribonuclease which digest rna and dna |
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Term
| absoprtion in small intestine |
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Definition
| you need small molecules to reach the absorptive epitheium and then into the blood. |
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Term
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Definition
passages of digestive nutrients from the gi tract or lymph. This process will occur by diffusion, facilitated diffusion, osmosis, and active transport. 90% of absorption gets absorbed in sm intestine. Stomache and lg will do remaining 10% |
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Term
| absorption of monosaccharides |
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Definition
- gi tract to cells: facillitated diffusion or active transport
- cells to the blood: facilitated diffusion
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Term
| absorption of amino acids, di/tri peptides |
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Definition
o GI Tract: by active transport.
o cell to blood: by diffusion |
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Term
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Definition
o GI Tract: fatty acids can be absorbed by simple diffusion. Larger fatty acids need to be carried across by a protein carrier called a myseal.
o Cells to blood: Larger fatty acids are carried by a lipoprotein, like chylomicrons. HDL and LDL also carry lipids. LDLs are bad bc they dump their lipids into arteries. |
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Term
| absorption of electrolytes |
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Definition
o GI Tract: active transport
o Cells to blood: active transport |
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Term
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Definition
o GI Tract: simple diffusion. B12 is active transport with intrinsic factor.
o Cells to blood: simple diffusion. |
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Term
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Definition
| terminal portion of gi tract. 5ft long. Extends from ileum to anus. |
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Term
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Definition
| completion of absorption, production of certain vitamins, formation and expulsion of feces. |
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Term
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Definition
mucosa
submucosa
muscularis
serosa |
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Term
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Definition
| simple columnar epithelium, lamina propria(areolar ct), muscularis mucosae(smooth muclse), absorptive & goblet cells located in intestinal glands |
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Term
| muslaris layer of lg intestine |
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Definition
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Term
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Definition
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Term
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Definition
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Term
| 4 regions of lg intestine |
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Definition
- cecum
- colon
- rectum
- anal canal
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Term
| mechanical digestion of lg intestine |
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Definition
passage of chyme from ileum to cecum is conrolled by ilececal sphincter
- gastroileal reflex
- haustral churning
- mass peristalsis
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Term
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Definition
| after a meal this occurs increasing peristalsis in the ileum forcing chyme into the cecum. Gastrin relaxes sphincter. |
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Term
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Definition
the haustra remain relaxed and become distended while they fill up with chyme, distension reaches a certain point the walls contract and squeeze contents into the next haustra |
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Term
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Definition
| occurs 3-4 times a day during or after meal. Begins in the middle of transverse colon, it is strong peristaltic wave that quickly drives contents of colon into rectum. |
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Term
| chemical digestion in lg intestine |
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Definition
| final stage of digestion is done by bacteria |
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Term
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Definition
| by the time chyme has remained in lg intestine for 3-10 hours it becomes a solid/semisolid do to water absorption, it is now called feces. |
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Term
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Definition
| water, inorganic salts, sloughed off epithelial cells, bacteria, products of bacteria decomposition, unabsorbed digested materials and indigestible parts of food. |
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