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GI PHYSIOLOGY & NUTRITION

GI PHYSIOLOGY & NUTRITION. Which gastrointestinal layer is characterized by having tough, fibrous connective tissue ? Mucosa Submucosa Muscle Serosa. Which gastrointestinal layer is characterized by having tough, fibrous connective tissue ? Mucosa Submucosa Muscle Serosa

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GI PHYSIOLOGY & NUTRITION

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  1. GI PHYSIOLOGY & NUTRITION

  2. Which gastrointestinal layer is characterized by having tough, fibrous connective tissue? • Mucosa • Submucosa • Muscle • Serosa

  3. Which gastrointestinal layer is characterized by having tough, fibrous connective tissue? • Mucosa • Submucosa • Muscle • Serosa The mucosa is the inner layer.

  4. Which intestinal layer accounts for the action of the peristaltic waves? A) serosa B) muscularis C) Submucosa D) mucous

  5. Which intestinal layer accounts for the action of the peristaltic waves? A) serosa B) muscularis C) Submucosa D) Mucous The muscularis has circular and longitudinal muscles that cause the food to move in peristaltic, forward waves.

  6. The _____ nervous system division usually stimulates and promotes digestion. A) somatic B) sympathetic C) Central D) Parasympathetic

  7. The _____ nervous system division usually stimulates and promotes digestion. A) somatic B) sympathetic C) Central D) Parasympathetic The impulses from the parasympathetic nervous division act to promote the forward movement of food and other digestive activities; the sympathetic pattern includes an inhibition of digestive activity such as constriction of a sphincter.

  8. The portion of the nervous system that is responsible for controlling secretion, absorption, and contraction of the GI tract at a local level is the: • Auerbach’s Plexus • Meissner’s Plexus • Myenteric Plexus • Parasympathetic NS • Sympathetic NS

  9. The portion of the nervous system that is responsible for controlling secretion, absorption, and contraction of the GI tract at a local level is the: • Auerbach’s Plexus • Meissner’s Plexus • Myenteric Plexus • Parasympathetic NS • Sympathetic NS The ANS controls GI function on a system-wide level. Auerbach’s & Myenteric Plexuses are different names for the same system. This system controls motor activity along the length of the gut. Meissner’s or Submucosal Plexuses are responsible for local control of GI function.

  10. In which part of the stomach does gastric mixing occur? • Fundus • Cardiac portion • Pylorus • Antrum • Body

  11. In which part of the stomach does gastric mixing occur? • Fundus • Cardiac portion • Pylorus • Antrum • Body The strong antral peristaltic contractions are responsible for the mixing of food with gastric secretions to produce chyme. The muscular layers in the cardiac portion, fundus, and body are too thin to create strong peristaltic movements required for mixing.

  12. Distension of the stomach: • Is associated w/ a decrease in peristaltic activity in the stomach • Decreases the tone of the LES • Causes an acute increase in pressure inside the resting stomach • Results in a potentially large increase in volume w/ very little pressure change

  13. Distension of the stomach: • Is associated w/ a decrease in peristaltic activity in the stomach • Decreases the tone of the LES • Causes an acute increase in pressure inside the resting stomach • Results in a potentially large increase in volume w/ very little pressure change As material enters the stomach, the muscle in the walls will relax, to allow a relatively large change in volume w/ a small pressure change. Relaxation is due to the property of plasticity.

  14. Gastric enzymes are secreted by the _____ cells. A) chief B) goblet C) parietal D) oxyntic

  15. Gastric enzymes are secreted by the _____ cells. A) chief B) goblet C) parietal D) oxyntic Chief (peptic) cells secrete enzymes while the parietal cells produce hydrochloric acid; parietal cells are also called oxyntic.

  16. The hormone enterogastrone: • Is secreted by the duodenum in response to duodenal filling • Accelerates gastric emptying • Causes G cell to produce gastrin • Causes the pyloric sphincter to open

  17. The hormone enterogastrone: • Is secreted by the duodenum in response to duodenal filling • Accelerates gastric emptying • Causes G cell to produce gastrin • Causes the pyloric sphincter to open Distension of the duodenum intiates release of enterogastrone from the mucosal cells of the duodenum. It delays gastric emptying by closing the pyloric sphincter & inhibiting production of gastrin.

  18. Proteins are digested or broken down by the _____ in the stomach. A) pepsinogen B) pepsin C) hydrochloric acid D) lipase

  19. Proteins are digested or broken down by the _____ in the stomach. A) pepsinogen B) pepsin C) hydrochloric acid D) lipase Pepsinogenis the inactive form that is activated by acidity and converted to pepsin; the term lipase refers to a general enzyme which catalyzes the breakdown of fats or lipids.

  20. Parasympathetic stomach impulses cause all of the following except which one? A) secretion of somatostatin B) inhibition of somatostatin C) secretion of gastrin D) promotes histamine

  21. Parasympathetic stomach impulses cause all of the following except which one? A) secretion of somatostatin B) inhibition of somatostatin C) secretion of gastrin D) promotes histamine Somatostatin normally inhibits the production of hydrochloric acid and parasympathetic nerves promote digestion; gastrin is a hormone which also promotes gastric activity.

  22. Gastrin secretion will stop when the stomach pH reaches _____. A) 7.0 B) 4.5 C) 1.5 D) 3.0

  23. Gastrin secretion will stop when the stomach pH reaches _____. A) 7.0 B) 4.5 C) 1.5 D) 3.0 One purpose of the hormone gastrin is to increase the acidity of the stomach; when the pH reaches 1.5 the gastrin is inhibited by negative feedback mechanisms.

  24. The alkaline tide occurs when _____ is excreted into the urine. A) HCl B) H+ C) bicarbonate ions D) phosphate ions

  25. The alkaline tide occurs when _____ is excreted into the urine. A) HCl B) H+ C) bicarbonate ions D) phosphate ions As the body attempts to maintain a balance of ions, -HCO3 ions are absorbed into the blood as H+ ions enter the stomach lining from the blood; this exchange of bicarbonate for hydrogen following a meal is called the alkaline tide.

  26. What is the stimulus for cholecystokinin release? A) chyme B) Lipids C) protein D) gastrin

  27. What is the stimulus for cholecystokinin release? A) chyme B) Lipids C) protein D) gastrin Chymerich in fats will stimulate the secretion of cholecystokinin from the intestine which will then cause the gall bladder to constrict.

  28. Which of the following slightly inhibits gastric secretion, stimulates pancreatic secretions high in digestive enzymes, causes contraction of the gallbladder, & causes relaxation of the hepatopancreaticampullar sphincter? • Gastrin • Secretin • CCK • GIP • Inhibin

  29. Which of the following slightly inhibits gastric secretion, stimulates pancreatic secretions high in digestive enzymes, causes contraction of the gallbladder, & causes relaxation of the hepatopancreaticampullar sphincter? • Gastrin Increases Gastric Secretion • Secretin Inhibits Gastric Secretion • CCK • GIP Inhibits Gastric Secretion • Inhibin

  30. Which of the following hormones secreted by the small instestines is known to increase gut motility? • Somatostatin • Urogastrone • Secretin • Serotonin • Neurotensin

  31. Which of the following hormones secreted by the small instestines is known to increase gut motility? • Somatostatin • Urogastrone • Secretin • Serotonin • Neurotensin Serotonin & Substance P & Motilin increase gut motility.

  32. Which of the following breakfasts would remain in the stomach the longest? • Toast, orange juice, and coffee • Black coffee • Fried eggs, bacon, and hash browns • I am hungry…Grrrrr!

  33. Which of the following breakfasts would remain in the stomach the longest? • Toast, orange juice, and coffee • Black coffee • Fried eggs, bacon, and hash browns • I am hungry…Grrrrr! 4 Factors in the Duodenum that influence gastric emptying are: fat – acid – hypertonicity – distension.

  34. Which of the following triggers the formation of the others? A) trypsin B) enterokinase C) carboxypeptidase D) chymotrypsin

  35. Which of the following triggers the formation of the others? A) trypsin B) enterokinase C) carboxypeptidase D) chymotrypsin Enterokinase from the small intestine catalyzes the conversion of trypsinogen to trypsin which then activates chymotrypsin and carboxypeptidase.

  36. Which of the following are not active in the duodenum? A) nuclease B) enterokinase C) pepsin D) amylase

  37. Which of the following are not active in the duodenum? A) nuclease B) enterokinase C) pepsin D) Amylase

  38. Secretin from the duodenum causes the pancreas to produce secretions rich in _____. A) proteolytic enzymes B) amylase C) lipase D) bicarbonate

  39. Secretin from the duodenum causes the pancreas to produce secretions rich in _____. A) proteolytic enzymes B) amylase C) lipase D) Bicarbonate Acid in the duodenum causes the release of the hormone secretin which stimulates the pancreas to produce a bicarbonate rich solution for the purpose of neutralizing the acidity.

  40. Which of the following hormones’ secretion is stimulated by acidity of chyme? • Gastrin • Secretin • CCK • GIP

  41. Which of the following hormones’ secretion is stimulated by acidity of chyme? • Gastrin • Secretin • CCK • GIP Secretin inhibits gastric secretion; stimulates pancreatic secretion high in bicarb ions; increases the rate of bile secretion; increases intestinal mucous secretion; decreases gastric motility.

  42. The hormone which causes the pancreas to secrete an enzyme rich fluid is _____. A) cholecystokinin B) secretin C) enterogastrone D) enterocrinin

  43. The hormone which causes the pancreas to secrete an enzyme rich fluid is _____. A) cholecystokinin B) secretin C) enterogastrone D) Enterocrinin Cholecystokinin is the hormone that causes the gall bladder to constrict. Secretin causes a bicarbonate-rich production.

  44. Which organ produces and secretes bile? A) liver B) gallbladder C) pancreas D) duodenum

  45. Which organ produces and secretes bile? A) liver B) gallbladder C) pancreas D) duodenum Bile is secreted by the liver and stored in the gallbladder.

  46. The Kupffer cells are phagocytic cells found in the _____. A) gallbladder B) pancreas C) intestine D) liver

  47. The Kupffer cells are phagocytic cells found in the _____. A) gallbladder B) pancreas C) intestine D) liver The liver Kupffer cells are phagocytic and also belong to as system of cells throughout the body called the RES (reticuloendothelial).

  48. Bile facilitates digestion by causing the _____ of fats. A) hydrolysis B) digestion C) catalysis D) emulsification

  49. Bile facilitates digestion by causing the _____ of fats. A) hydrolysis B) digestion C) catalysis D) emulsification Bile salts contain unique molecules that have polar and non-polar regions that cause large fat globules to physically break up into smaller units.

  50. Bile salts combine with fatty acids to form complexes called _____ that facilitate absorption. A) chylomicrons B) micelles C) globules D) lipoproteins

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