Term
| what is the basic anatomy of the digestive track |
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Definition
| mouth, esophagus, stomach, small intestine, large intestine, rectum and anus |
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Term
| what is the major reaction involved in the digestion of macromolecules |
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Definition
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Term
| where and when does digestion start |
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Definition
| digestion starts in the mouth with alpha amylase, a enzyme in saliva that breaks down large carbohydrates into multiple polysaccharides |
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Term
| what is peristaltic action |
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Definition
this is the movement of bolus, semi-digested food, from the mouth to the stomach via the esophagus
the movement has been described in comparison to a tooth paste tube |
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Term
| does digestion occur in the esophagus |
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Definition
| no, no digestion occurs in the esophagus |
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Term
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Definition
| it both mixes and stores food, reducing it to a semifluid mass called chyme |
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Term
| what is the gross anatomy of the stomach |
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Definition
it has gastric pits
within each of the gastric pits, there are four types of cells: mucous cells, chief (peptic) cells, parietal (oxyntic) cells and G cells |
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Term
| what are some of the functions of the mucous cells |
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Definition
lubricate the stomach walls and exocrine glands to prevent damage, and also protects the epithelial lining from the acidic environment
mucous is composed of glycoproteins and electrolytes |
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Term
| what is the main function of chief cells |
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Definition
| these are located deep in the exocrine system and secrete pepsinogen, a precursor to pepsin. once pepsinogen is activated by the low pH of the stomach it begins to denature proteins in the stomach |
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Term
| where does protein digestion begin |
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Definition
| in the stomach! but, no absorption takes place here |
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Term
| what is the function of parietal cells |
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Definition
| to secrete HCL, the major process of the mechanism takes place within the lumen |
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Term
| how do G cells and parietal cells work together |
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Definition
| G cells secrete gastrin into the blood stream and this stimulates the parietal cells to manufacture and secrete HCl |
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Term
| what are the major hormones that affect the secretion of the stomach juices |
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Definition
Ach increase the secretion of all stomach cells
gastrin and histamine increase the secretion of HCl secretion |
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Term
| about 90% of digestion and absorption occurs where |
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Definition
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Term
| where in the small intestine does the majority of digestion occur |
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Definition
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Term
| where in the small intestine does the majority of absorption occur |
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Definition
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Term
| what do microvilli do and where are they located |
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Definition
microvilli are located within the small intestine-most likely in the jejunum and ileum
they increase the surface area of the stomach, to increase absoption efficiency |
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Term
| within each microvilli their is a lymph vessel called |
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Definition
| lacteal which takes up the nutrients absorped by the microvilli |
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Term
| a collection of microvilli are called and what do they contain |
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Definition
| brush border and they contain carbohydrate, protein and nucleotide enzymes |
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Term
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Definition
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Term
| the pancreas releases a bunch of enzymes, but which one activates all the others |
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Definition
| trypsin is activated by the enzyme enterokinase, then activated trypsin activates the other enzymes |
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Term
| what do the enzymes trypsin and chymotypsin do |
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Definition
they degrade proteins into small polypeptides
these polypeptides are further reduced by enterocytes in the brush border |
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Term
| what does the enzyme pancreatic amylase do |
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Definition
| it degrades nearly all carbohydrates into small glucose polymers |
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Term
| how do lipase and bile work hand in hand |
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Definition
bile emulsifies fat into smaller particles without changing its chemical properties, therefore increasing the surface area of each fat particle (bile has no role in the digestion of the fat, it just seperates them)
this is where lipase comes in, lipase degrades fat |
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Term
| what is the major function of the large intestine |
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Definition
| water absorption and electrolyte absorption-when this fails you have diarrhea |
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Term
| why is gastric imhibitory peptide release after a meal |
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Definition
| gastric inhibitory peptide increases insulin levels thus preparing the body for absorbing more fat and protein |
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Term
| what is the postabsorptive fate of major nutrients |
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Definition
| nutrients are processd and carried to individual cells for use |
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Term
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Definition
| the formation of glycogen |
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Term
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Definition
| when blood glucose levels are low, glycogenolysis occurs and glucose is returned to the blood |
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Term
| where are large amounts of glycogen stored |
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Definition
| the liver and muscle cells, when these cells have reached their saturation levels, carbohydrates are converted to fatty acids |
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Term
| before entering the blood, all proteins are broken down into |
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Definition
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Term
| what does albumin do for free floating fatty acids |
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Definition
| it binds to them and carries them through the body because fats are insoluble in water |
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Term
| where is the vena cava located |
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Definition
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Term
| what are some functions of the liver |
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Definition
| blood storage, blood filter, carbohydrate metabolism, protein metabolism, fat metabolism, detoxification, vitamin storage & erythrocyte destruction |
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Term
| where are antibodies made |
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Definition
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Term
| how does the bloods pH respond to when the liver mobilizes fat or protein |
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Definition
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Term
| what is the function of the kidney |
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Definition
to excrete waste products, such as urea, uric acid, ammonia and phosphate
to maintain homeostasis of the body fluid colume and solute
to help control plasma pH |
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Term
| what is the gross anatomy of a kidney |
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Definition
| it is fist-size, the outer portion of it is called cortex and the inner is called medulla |
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Term
| describe how urine makes its way out |
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Definition
| urine is created by the kidney, dumped into the renal pelvis, into the ureter which carries urine to the bladder, the bladder is emptied via urethra |
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Term
| where is most reabsorption taken place |
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Definition
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Term
| what does the distal tube do |
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Definition
| reabsorbs sodium and calcium, but secretes potassium, hydrogen and HCO3 |
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Term
| in the kidney, where does filtration occur |
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Definition
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Term
| in the kidney, where does reabsorption occur |
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Definition
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Term
| in the kidney what does the loop of Henle do |
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Definition
| concentrates solute in the medulla |
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