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50 Cards in this Set
- Front
- Back
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the what is where we first encounter the general structure of the gut tube |
esophagus |
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esophogus like most parts of the gut tube, there are two layers in the muscularis |
circular layer that closes off the lumen when contracted longitudinal lyer that contracts in waves to move things along |
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the valve that allows substances to pass from the pharynx to esphagus is the |
upper esophageal sphincter |
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the valve between esophagus and stomach is the |
lower esophageal sphincter
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the superior 1/3 of the esophagus is |
striated muscle under vonluntary control |
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the lower 2/3 of esophagus |
smooth muscle under autonomic control |
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deglutition |
is the process of swallowing |
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the process that moves food, later chyme, later feces, in the GI tract |
peristalsis |
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three phases of swallowing |
voluntary, pharyngeal, esophageal |
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pharyngeal stage of swallowing |
when bolus of food is in the oro/laryngopharynx. this stage where food and water are kept out of the trachea |
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esophageal stage of swallowing |
the upper esophageal sphincter opens, and the autonomic process of peristalsis begins |
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food and liquid leaving the esophagus pass through |
lower esophageal sphincter also called cardiac sphincter |
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the lower esophageal sphincter sometimes fails to tightly close causing |
gastro-esophageal reflux disease or GERD |
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GERD can be caused by |
increased abdominal pressure or obesity |
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THe stomach has five regions and two curves |
Cardia, Fundus, body, pyloric antrum, pyloric canal greater curvature, lesser curvature |
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the what is the point at wich the espophagus crosses the diaphragm to become the stomack |
cardia |
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the what represents the end of the stomach and the outlet for stomach contents |
pyloric sphincter |
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the pyloric sphincter opens into the what which is the initial segment of the small intestine |
duodenum |
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in the stomach, the what layer is specialized for the digestion of food |
mucosa |
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the specialization of stomach is |
gastric pits |
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gastric pits is lined with |
simple columnar epithelium |
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the bottom half of gastric pits has |
a higher concetration of glandular cells that collectively are called gastric glands |
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along the stomach lumen, epithelial cells and what predominate |
surface mucous cells |
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gastric pits has a number of |
secretory cells |
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mucous neck cells in stomach |
secrete protective mucus |
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parietal cells do what |
they have specialized protein pumps that dump H+ and Cl- ions into the lumen making HCl -stomach acid they secrete intrinsic factor |
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what is critical for absorption of vit b12 |
intrinsic factor |
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decreased production of intrinsic factor leads to |
pernicious anemia |
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cheif cells secrete the enzymes |
pepsinogen and lipase |
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g cells secret |
gastrin |
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g cells are an example of |
enteroendocrine cells a kind of hormonal system in GI tract |
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oblique muscle layer |
aids in the stomach's ability to churn substraces and speed digestion |
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carbon dioxide and water in the stomach are turned into carbonic acid by the enzyme |
carbonic anhydrase |
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carbonic anhydrase found in |
parietal cells |
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parietal cells of stomach secrete |
hydrochloric acid to aid in digestion and protect from invaders |
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making h+ ions |
-water+CO2 makes carbonic acid which then buffers to H+ and HCO3- -H+ pumped out, K+ pumped in by active transport |
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carbonic acid |
H2CO3 |
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making Cl- ions |
-Cl- concetrated in cell by antiporter (dumps HCO3- into bloodstreem) -Cl- concentration high in parietal cell, flows into stomahc lumen through Cl- channel |
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HCO2- is used to buffer |
the blood |
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disease can increase |
the secretion of stomach acid, or more commonly decrase secretio of protective materials |
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several neurotransmitter/hormones up-regulate HCl secretion |
ach from parasympathetic stimulation gastrin from G cells histamine from mast cells in lamina propria |
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failure of the pancrease to make what can result duodenal ulcers |
bicarbonate |
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drugs to reduce ulcers |
inhibiting the proton pump (omeprozole, lansoprazole, esomeprazole) they reduce the secretion of H+Cl- by parietla cells and can reduce the symptoms of gastroesophageal reflux disease |
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cell types of stomach |
surface muscous cells mucous neck cells chief cells g cells parietal cells |
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surface mucous cells secrete what |
mucous |
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mucous neck cells |
secrete mucus |
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chief cells secrete |
pepsinogen and lipase |
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g cells secrete |
gastrine hormone |
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parietal cells secrete |
hydrochloric acid and intrinsic factor |
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gastrin equals |
motility |
