Term
| carbohydrates, proteins, fats |
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Definition
| what are the macronutrients? |
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Term
| Na+, K+, Ca++, Fe++, Cl-, PO4- |
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Definition
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Term
1) motility
2) large SA
3) appropriate pH
4) hydrolytic enzymes
5) emulsifying factors
6) specialiezed cells
7) specific transport mechanisms (carriers, pumps, pores)
8) energy
9) blood or lymph flow |
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Definition
| what are the essential factors for digestion? |
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Term
| segmentation contraction, and peristaltic waves |
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Definition
| what are the 2 types of small intestine motility? |
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Term
1) basal electrical rhythm (BER)
2) enteric nervous system
3) response to distention
4) intestinal transit time
5) ileo-cecal sphincter |
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Definition
| what things control small intestine motility? |
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Term
|
Definition
| what % of nutrients are absorbed in the small intestine? |
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Term
| 5 minutes (then inhibitors kick in) |
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Definition
| how long does it take to move food from the mouth to the jejunum? |
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Term
| to increase the SA for absorbtion etc. |
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Definition
| what is the purpose of villi and crypts in the small intestine? |
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Term
| cells on the villi have folds in their apical membranes (microvilli) |
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Definition
| what is the brush border? |
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Term
|
Definition
| what is the surface area of the small intestine? |
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Term
| H+ ions, bile HCO3-, pancreatic HCO3- |
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Definition
| what factors change the luminal pH? |
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Term
amylase: salivary, pancreatic
lipase: pancreatic
proteases: pancreatic
disaccharidass: brush border
peptidases: brush border |
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Definition
| where is amylase secreted? lipase? proteases? disaccharidases? peptidases? |
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Term
|
Definition
| does the small intestine absorb disaccharides? |
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Term
| (stomach?), bile acids and lecithin |
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Definition
| what are the emulsifiers? |
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Term
| milk is a carb(lactose is a disaccharide) |
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Definition
| what type of macronutrient is milk considered? |
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Term
| starch, glycogen, sucrose, lactose, fructose |
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Definition
| what are the carb digestion dietary substances? |
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|
Term
amylase(with high capacity) rapidly hydrolyzes to form maltose, maltotriose, alpha limit dextrins, and glucose
starch is completely digested within the first meter of the small intestine |
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Definition
| what is the first stage of starch/carb digestion? when does this take place? |
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Term
alpha limit dextrins = glu-glu-glu (3+ glucose)
maltose: glu-glu
maltotriose: glu-glu-glu
sucrose: fru-glu
lactose: gal-glu |
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Definition
| describe the structure of alpha limit dextrins, maltose, maltotriose, sucrose, lactose |
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Term
| sucrose, lactose, maltose, maltotriose, alpha limit dextrins are hydrolyzed by enzymes in the brush border of enterocytes yielding 99% glu, 0.5% gal, 0.5% fru |
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Definition
| where does stage 2 carb digestion occur? |
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Term
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Definition
| what enzyme dissapears at weaning in most humans? |
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Term
the stomach: pepsin
then continues 2/3 through the small intestine via pancreatic proteases at the brush border yielding di, and tri-peptides and amino acids |
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Definition
| where does protein digestion begin? what enzyme? what digests them from there? |
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Term
| di/tri-peptids, hydrolases |
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Definition
| proteases are secreted by the pancreas, yeilding ____, then the brush border ______, leades to amino acids and dipeptides & are transported through the cell |
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Term
|
Definition
| what is the daily fat intake? the daily protein intake? |
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Term
|
Definition
| what form is most dietary fat? |
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|
Term
|
Definition
| where does emulsification for fat digestion begin? |
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Term
| 2 fatty acids and a monoglyceride |
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Definition
| what does pancreatic lipase produce (acting as a "hydrolase" for fat)? |
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Term
| makes solublized micelles |
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Definition
| what does digestion do to fat? |
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Term
|
Definition
| proteins bind to _____ regions of fat molecules and coat the surface, the biles salts aid/enhance this process |
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Term
| as micelles it diffuses based on a concentration gradient |
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Definition
| how is fat absorbed by enterocytes? |
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Term
| the micelles are recreated into TAG's and then packaged into a chylomicron (fat+ protein) then they diffuse out the basal side into the LYMPH |
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Definition
| describe what happens to a micelle in an enterocyte, and where it goes from there. |
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Term
| Sodium!! for the Na+/K+ pump to make a concentration gradient for secondary active transport |
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Definition
| what is CENTRAL to absorbtion? |
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Term
| the basal surface, uses ATP energy |
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Definition
| where is the NA+/K+ pump on an enterocyte? does it use energy? |
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Term
| secondary active transport |
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Definition
| how do glucose and amino acids get into the enterocytes? (in general) |
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|
Term
facilitated diffusion down the concentration gradient (uses sodium cotransport
galactose is about the same as glucose
fructose uses facilitated diffusion all the way through the enterocyte but WITHOUT sodium, then it is converted to glucose before reaching the basal side |
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Definition
| how does glucose get into an enterocyte? galactose? fructose?(more specific) |
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|
Term
| lack of sanitation (dirty food and water), cholera, childhood diseases |
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Definition
| what can cause deadly diarrhea? |
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Term
| water + sugar + salt (stops electrolyte depletion) |
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Definition
| what is the magic treatment of diarrhea? |
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Term
| sugars (glu) is transported via secondary active transport with sodium, the water follows the sugar |
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Definition
| how does water get into the cell? |
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|
Term
di/tri-peptides, they use H+ to co-transport into the cell
(H+ pumped back out with antiport Na+/H+ pump) |
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Definition
| which diffuses more rapidly, amino acids or di/tri-peptides? |
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Term
|
Definition
| what ion uses paracellular diffusion for absorbtion? |
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|
Term
calcium: first 1/3 of small intestine
iron: upper 1/2 of small intestine |
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Definition
| where is calcium absorbed, iron? |
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Term
|
Definition
| what does the colon have a high capacity to absorb? |
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Term
|
Definition
| what kind of gas forms in the colon? how? |
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Term
hyper: diarrhea
hypo: constipation |
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Definition
| a hyper functioning colon causes what? a hypo functioning colon causes what? |
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Term
| cecum and ascending (proximal) colon |
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Definition
| where is most of the feces storage in the colon? |
|
|
Term
slow segmentation (haustra)
peristalsis (mass movement = poop sensation) |
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Definition
| what causes colonic motility? |
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|
Term
slow segmentation (haustra)
peristalsis (mass movement = poop sensation) |
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Definition
| what causes colonic motility? |
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|
Term
| contraction of the abdominal muscles against the diaphragm causes increased abdominal pressure and leads to removal of feces |
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Definition
| what is the valsalva in regards to defecation? |
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|
Term
1)overflow: overwhelm the small intestine with H20 and salt
2)osmotic: non-absorbable substances go through the GI tract (like milk of magnesia)
3)inflammatory: disease of the intestinal lining such as ulcerative colitis, leading to epithelial death |
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Definition
| what are the 3 types of diarrhea? describe each |
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