Florida International University

BIO PCB 4023

Chapter 20

1)Which of the following is NOT a basic process of the gastrointestinal system?

1. 1. digestion B) motility C) absorption D) secretion E) filtration
2. Which of the following is the correct order of the layers of the gastrointestinal tract wall, from lumen to external surface?
   1. submucosa, mucosa, serosa, muscularis externa
   2. serosa, mucosa, submucosa, muscularis externa
   3. mucosa, submucosa, serosa, muscularis externa
   4. serosa, muscularis externa, submucosa, mucosa
   5. mucosa, submucosa, muscularis externa, serosa
3. Which of the following correctly lists the three portions of the mucosa?
   1. adventitia, muscularis externa, mucous membrane
   2. serosa, muscularis mucosae, muscularis externa
   3. muscularis mucosae, mucous membrane, submucosa
   4. mucous membrane, lamina propria, muscularis mucosae
   5. adventitia, lamina propria, muscularis externa
4. Enterocytes of the mucous membrane of the mucosal layer are classified as    cells if they secrete fluids and enzymes into the lumen and    cells if they release hormones into the bloodstream.
   1. absorptive : endocrine
   2. exocrine : absorptive
   3. endocrine : absorptive
   4. endocrine : exocrine
   5. exocrine : endocrine
5. What layer of the mucosa is connective tissue that contains blood vessels and lymphatic vessels?
   1. submucosal plexus
   2. mucous membrane
   3. muscularis mucosae
   4. serosa
   5. lamina propria
6. What is the thin layer of smooth muscle cells whose contraction stirs the lumenal contents and promotes contact with the mucosal membrane?
   1. muscularis mucosae
   2. muscularis externae
   3. serosa
   4. muscularis internae
   5. myenteric plexus

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7. What layer of the gastrointestinal wall is a thick layer of connective tissue that provides the gastrointestinal tract with much of its elasticity and distensibility?
   1. mesentery
   2. serosa
   3. peritoneum
   4. submucosa
   5. lamina propria
8. The enteric nervous system receives its inputs from
   1. autonomic neurons only.
   2. somatic motor neurons only.
   3. sensory neurons in the wall of the gastrointestinal tract only.

8. 4. both autonomic neurons and sensory neurons in the wall of the gastrointestinal tract.
   5. both somatic motor neurons and sensory neurons in the wall of the gastrointestinal tract.
9. The muscularis externa contains which of the following muscle groups?
   1. a muscularis mucosae, which lubricates as it contracts
   2. an inner circular layer capable of slow-wave potentials only
   3. an outer longitudinal layer that requires neural input for contraction
   4. both an inner circular and an outer longitudinal layer
   5. an inner circular and outer longitudinal layer, and a muscularis mucosae
10. Where do slow-wave potentials occur?
    1. submucosal plexus
    2. myenteric plexus
    3. muscularis mucosae
    4. inner circular muscle layer of the muscularis externa
    5. outer longitudinal muscle layer of the muscularis externa
11. The              is a layer of epithelial cells on the outer side of the serosa that secretes a watery lubricating fluid that makes it easier for organs to slide past one another.
    1. mesothelium
    2. myenteric plexus
    3. endothelium
    4. mesentery
    5. submucosa
12. What membrane lines the abdominal cavity?
    1. adventitia
    2. mesothelium
    3. serosa
    4. mesenteries
    5. peritoneum

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13. What is the technical word for chewing?
    1. haustration
    2. segmentation
    3. mastication
    4. micturition
    5. accommodation
14. As the food is broken into smaller pieces in the mouth, it is combined with     that facilitates its movement down the esophagus.
    1. pancreatic juices
    2. gastric juices
    3. chyme
    4. saliva
    5. amylase
15. What is a ring of skeletal muscle that regulates the movement of a bolus into the esophagus?
    1. lower esophageal sphincter
    2. upper esophageal sphincter
    3. glottis
    4. epiglottis
    5. pyloric sphincter
16. Gastric reflux occurs when material flows backwards through which of the following structures?

16. 1. glottis
    2. lower esophageal sphincter
    3. upper esophageal sphincter
    4. pyloric sphincter
    5. epiglottis
17. What is a mixture of food particles with gastric juice called?
    1. chyme
    2. saliva
    3. fundus
    4. gastric secretions
    5. bolus
18. The flow of chyme from the stomach to the small intestine is physically regulated by the
    1. epiglottis.
    2. lower esophageal sphincter.
    3. glottis.
    4. gastroileal sphincter.
    5. pyloric sphincter.

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19. What are rugae?
    1. folds in the small intestine that increase the surface area for absorption
    2. folds in the large intestine that increase the surface area for absorption
    3. folds in the stomach that can flatten to expand the stomach volume
    4. a motility pattern of the large intestine
    5. a motility pattern of the stomach
20. What cells secrete pepsinogen into the lumen of the stomach?
    1. neck B) goblet C) G D) parietal E) chief
21. What cells function to secrete hydrogen ions into the lumen of the stomach?
    1. chief B) neck C) goblet D) parietal E) G
22. What do parietal cells secrete?
    1. hydrogen ions only
    2. pepsinogen only
    3. intrinsic factor only
    4. both hydrogen ions and pepsinogen
    5. both hydrogen ions and intrinsic factor
23. What do neck cells of gastric pits secrete?
    1. gastrin
    2. hydrogen ions
    3. intrinsic factor
    4. mucus
    5. pepsinogen
24. Which of the following is NOT a normal function of the high acidity of the stomach?
    1. protect against illness
    2. activate vitamin B12
    3. activate pepsin
    4. denature proteins
    5. destroy foodborne bacteria
25. Once the chyme begins to enter the duodenum, it must first be           before any of the enzymes in the

pancreatic juices can be activated.

1. 1. acidified
   2. hydrated
   3. dehydrated
   4. phosphorylated
   5. deacidified

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26. What protects the stomach wall from the acidic lumenal contents?
    1. a layer of parietal cells
    2. the presence of rugae
    3. a layer of adipose tissue lining the gastric mucosa
    4. the gastric mucosal barrier
    5. the gastric coat
27. To increase the absorptive efficiency of the small intestine, the surface area of the mucosa is increased by the presence of folds in the wall called                                                   , and projections of the cell membrane called                   .
    1. lacteals : rugae
    2. microvilli : lacteals
    3. microvilli : villi
    4. rugae : lacteals
    5. villi : microvilli
28. Which of the following is the correct order of the components of the small intestine, from stomach to colon?
    1. duodenum, ileum, jejunum
    2. duodenum, jejunum, ileum
    3. jejunum, duodenum, ileum
    4. jejunum, ileum duodenum
    5. ileum, jejunum, duodenum
29. A lacteal is a            located in           .
    1. nerve : submucosal plexus
    2. patch of immune tissue : submucosa
    3. capillary : villus
    4. nerve : myenteric plexus
    5. lymphatic vessel : villus
30. What is the brush border?
    1. villi from epithelial cells lining the small intestine
    2. microvilli from parietal cells
    3. villi from epithelial cells lining the stomach
    4. microvilli from epithelial cells lining the small intestine
    5. villi from parietal cells
31. What do the secretory cells in the crypts of Lieberkühn secrete?
    1. succus entericus
    2. gastric juice
    3. pancreatic juice
    4. bile
    5. intestinal juice

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32. Blood from the intestinal capillaries drains into what blood vessel before entering the hepatic portal vein?
    1. hepatic vein
    2. coeliac vein
    3. intestinal vein

32. 4. mesenteric vein
    5. hepatic artery
33. What region of the colon serves primarily as a storage depot for whatever material remains in the lumen after absorption has occurred?
    1. resected B) transverse C) descending D) sigmoid E) ascending
34. What is the primary function of the colon?
    1. further digest fats within the chyme
    2. reduce the volume of the chyme
    3. regulate absorption of carbohydrates and amino acids
    4. further digest protein within the chyme
    5. further absorb carbohydrates
35. Which of the following structures is NOT part of the large intestine?
    1. colon
    2. rectum
    3. cecum
    4. vermiform appendix
    5. anus
36. Which of the following sphincters is composed of skeletal muscle?
    1. pyloric sphincter only
    2. upper esophageal sphincter only
    3. external anal sphincter only
    4. both the pyloric and upper esophageal sphincters
    5. both the upper esophageal and external anal sphincters
37. Which of the following is NOT one of the components of saliva?
    1. lysozymes
    2. bicarbonate ions
    3. amylases
    4. lipases
    5. mucus
38. Which of the following is NOT one of the components of exocrine pancreatic secretions?
    1. sucrose B) lipase C) protease D) nuclease E) amylase

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39. What enzymes, secreted by the exocrine pancreas, degrade fats?
    1. amylases
    2. lipases
    3. proteases
    4. endopeptidases
    5. nucleases
40. Which of the following secretes a bicarbonate-rich fluid?
    1. pancreas only
    2. salivary glands only
    3. liver only
    4. both salivary glands and pancreas
    5. salivary glands, pancreas, and liver
41. Which of the following secretes lipase?
    1. liver only
    2. pancreas only

41. 3. salivary glands only
    4. both salivary glands and pancreas
    5. pancreas and liver
42. Which of the following is NOT one of the functions of the liver?
    1. removal of aged erythrocytes
    2. synthesis of albumin
    3. secretion of enzymes for digestion
    4. secretion of bile
    5. synthesis and modification of hormones
43. What degradation by-product of hemoglobin is removed from the blood by the liver, conjugated, and then secreted into the bile?
    1. lipoproteins
    2. urea
    3. uric acid
    4. bilirubin
    5. iron
44. In order to convert amino acids to gluconeogenic precursors, their ammonium ion must be removed in the liver, which is then converted to what substance, thereby making it water soluble enough to be excreted by the kidneys?
    1. ammonia B) uric acid C) urea D) nitrogen E) bilirubin

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45. Which of the following is NOT one of the wastes eliminated by the liver in bile?
    1. cholesterol
    2. trace metals
    3. certain drugs
    4. urea
    5. bilirubin
46. Which of the following is NOT one of the hormone-related functions of the liver?
    1. secretion of hormone-binding proteins
    2. hormone synthesis
    3. hormone degradation
    4. hormone modification
    5. hormone storage
47. The flow of bile from the liver and juices from the exocrine pancreas converge at what structure?
    1. bile duct
    2. ampulla of Vater
    3. common bile duct
    4. gallbladder
    5. common hepatic duct
48. One side of a hepatocyte faces the blood while the other faces what?
    1. enterocyte
    2. sinusoid
    3. common hepatic duct
    4. bile canaliculus
    5. acinar cells
49. What is the functional unit of the liver?
    1. lobule
    2. bile canaliculi

49. 3. hepatocyte
    4. lobe
    5. sinusoid
50. What are liver sinusoids?
    1. air-filled cavities in the liver
    2. blood-filled cavities that exchange material with the hepatocytes
    3. the pathway for bile to exit the liver
    4. bile-filled cavities that exchange material with the hepatocytes
    5. the site of bile synthesis

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51. What are Kupffer cells?
    1. macrophages in the liver
    2. cells of the stomach that secrete hydrogen ions
    3. hepatocytes
    4. cells lining the crypts of Lieberkühn
    5. cells lining the pancreatic duct
52. The enzyme amylase is able to cleave glycogen and starch into
    1. disaccharides only.
    2. limit dextrins only.
    3. monosaccharides only.
    4. both disaccharides and limit dextrins.
    5. both monosaccharides and disaccharides.
53. Which of the following is NOT an enzyme that acts on the products of amylase digestion of glycogen and starch?
    1. galactase
    2. maltase
    3. sucrase
    4. dextrinase
    5. glucoamylase
54. The absorption of glucose involves      across the apical membrane and    across the basolateral membrane.
    1. secondary active transport : secondary active transport
    2. facilitated diffusion : facilitated diffusion
    3. secondary active transport : primary active transport
    4. secondary active transport : facilitated diffusion
    5. simple diffusion : facilitated diffusion
55. Where are enzymes that breakdown disaccharides located?
    1. in the lumen of the large intestine
    2. on the basolateral membrane of enterocytes
    3. inside enterocytes
    4. in the lumen of the small intestine
    5. on the apical membrane of enterocytes
56. The absorption of fructose across the apical membrane of the lumenal epithelial cells occurs through what process?
    1. sodium-linked secondary active transport
    2. primary active transport
    3. paracellular transport
    4. facilitated diffusion
    5. diffusion

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57. The digestion of proteins begins in the    with the activation of the zymogen     .
    1. small intestine : trypsinogen
    2. stomach : procarboxypeptidase
    3. stomach : pepsinogen
    4. small intestine : chymotrypsinogen
    5. mouth : pepsinogen
58. What enzyme is responsible for cleavage of the amino acid at the amine portion of the peptide fragment?
    1. carboxypeptidase
    2. aminopeptidase
    3. chymotrypsin
    4. trypsin
    5. enterokinase
59. What enzyme activates procarboxypeptidase?
    1. carboxypeptidase
    2. trypsin
    3. enterokinase
    4. pepsin
    5. aminopeptidase
60. Proteolytic enzymes secreted in pancreatic juice are stored in secretory cells of the pancreas as
    1. zymogens.
    2. pepsinogen.
    3. limit dextrins.
    4. chylomicrons.
    5. bile salts.

61. What enzyme cleaves trypsinogen to trypsin?
    1. amylase
    2. enterokinase
    3. pepsin
    4. procarboxypeptidase
    5. chymotrypsin
62. Many individual amino acids enter the epithelial cells that line the lumen of the digestive tract via what transport process?
    1. primary active transport
    2. simple diffusion
    3. paracellular transport
    4. sodium-linked secondary active transport
    5. facilitated diffusion

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63. In order to begin the process of fat digestion, the fat globules must be
    1. emulsified by trypsin.
    2. coalesced by bile salts.
    3. emulsified by bile salts.
    4. emulsified by lipases.
    5. coalesced by lipase.
64. Emulsification aids in the digestion of fats by
    1. beginning the process of degrading the triglycerides within the fat globule.
    2. increasing the surface area of the fat globule exposed to enzymes.

64. 3. the ability of bile salts to activate lipases that digest fats.
    4. increasing the number of hydrophobic residues on the surface of the fat globule.
    5. increasing the number of fat globules.
65. Pancreatic lipase degrades triglycerides into a
    1. monoglyceride and 1 free fatty acid.
    2. glycerol and 3 free fatty acids.
    3. monoglyceride and 2 free fatty acids.
    4. diglyceride and 1 free fatty acid.
    5. triglyceride whose free fatty acids have been shortened 2 carbons at a time.
66. Digestion products of lipases are readily exchanged in the lumen with
    1. polysaccharides.
    2. low-density lipoproteins.
    3. cholesterol.
    4. micelles.
    5. chylomicrons.

67. Bile salts are recycled by the
    1. common bile duct.
    2. hepatic arteries.
    3. enterohepatic circulation.
    4. biliary circulation.
    5. mesenteric arteries.
68. The products of fat degradation are absorbed in the small intestines by what transport process?
    1. facilitated diffusion
    2. sodium-linked secondary active transport
    3. primary active transport
    4. simple diffusion
    5. paracellular transport

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69. Once the degradation products of triglycerides have entered the epithelial cells that line the small intestines, they
    1. are reassembled into triglycerides and packaged by the Golgi apparatus into micelles.
    2. are further degraded to glycerol and a free fatty acid, which are packaged by the Golgi apparatus into chylomicrons.
    3. are reassembled into triglycerides and packaged by the Golgi apparatus into chylomicrons.
    4. are reassembled into triglycerides and released into the blood where they can be incorporated into chylomicrons.
    5. cross the basolateral membrane and enter the circulation where they will be embedded into a chylomicron.

70. Lipids are absorbed as         into             .
    1. chylomicrons : lacteals
    2. fatty acids and monoglycerides : mesenteric capillaries
    3. chylomicrons : mesenteric capillaries
    4. micelles : mesenteric capillaries
    5. micelles : lacteals
71. Vitamin B12 is absorbed in the       through            .
    1. jejunum : facilitated diffusion
    2. duodenum : facilitated diffusion
    3. ileum : complexing with intrinsic factor
    4. jejunum : complexing with intrinsic factor

71. 5. duodenum : cotransport with sodium
72. A lack of intrinsic factor can result in
    1. diarrhea.
    2. aplastic anemia.
    3. diabetes.
    4. pernicious anemia.
    5. immune suppression.

73. The absorption of sodium throughout the small intestine is driven by  transport and is typically linked to the absorption of       .
    1. active : chloride
    2. passive : glucose
    3. passive : bicarbonate
    4. active : bicarbonate
    5. active : glucose

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74. In the jejunum, bicarbonate is     , while in the ileum and colon, bicarbonate is .
    1. secreted : secreted
    2. secreted : absorbed
    3. absorbed : absorbed
    4. absorbed : secreted
    5. absorbed : not transported in either direction
75. Carbonic anhydrase is located in which of the following digestive structures?
    1. parietal cells only
    2. salivary glands only
    3. lumen of the small intestine only
    4. both salivary glands and parietal cells
    5. both parietal cells and lumen of the small intestine
76. Which of the following substances does NOT require the interaction with a protein in the intestinal tract to be absorbed?
    1. iron
    2. vitamin B12
    3. fat-soluble vitamins
    4. sodium
    5. calcium
77. The central component of the long reflex pathway typically involves the         nervous system, which acts to promote an increase in gastrointestinal activity.
    1. sympathetic
    2. intrinsic
    3. enteric
    4. parasympathetic
    5. somatic
78. Gastric-phase control of gastrointestinal function refers to its site of origin, which is what?
    1. the stomach
    2. the central nervous system
    3. the colon
    4. the intestines
    5. the pancreas
79. Which of the following is NOT one of the hormones released by the gastrointestinal tract that regulates its

function?

79. 1. glucose-dependent insulinotropic peptide
    2. glucose inhibitory peptide
    3. cholecystokinin
    4. secretin
    5. gastrin  13
80. Which of the following is an enterogastrone?
    1. bile
    2. monoglyceride
    3. gastrin
    4. cholecystokinin
    5. epinephrine
81. What does the secretion of leptin cause?
    1. decreased gastric secretion into the gastrointestinal tract
    2. increased pancreatic secretion into the gastrointestinal tract
    3. increased bile secretion
    4. increased motility of the gastrointestinal tract
    5. decreased sensation of hunger
82. What causes leptin secretion to increase?
    1. increased glycogenolysis in skeletal muscle cells
    2. decreased synthesis of triglycerides in adipose cells
    3. decreased synthesis of glycogen in liver cells
    4. increased gluconeogenesis in liver cells
    5. increased storage of calories in adipose cells
83. Obesity predisposes a person for development of all of the following diseases EXCEPT
    1. rickets.
    2. hypertension.
    3. liver disease.
    4. heart disease.
    5. atherosclerosis.
84. A person is considered obese if their body fat composition is what percentage above normal? A) 30 B) 10 C) 20 D) 40 E) 50

85. What cell type secretes resistin?
    1. hepatocytes only
    2. macrophages only
    3. G cells only
    4. adipocytes only
    5. adipocytes and macrophages

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86. The increase in absorbed nutrients in blood will cause secretion of what hormone to increase, thereby decreasing the sensation of hunger?
    1. insulin
    2. secretin
    3. gastrin
    4. cholecystokinin
    5. glucagon
87. The presence of food in the duodenum will cause secretion of what hormone to increase, thereby decreasing

the sensation of hunger?

87. 1. secretin
    2. gastrin
    3. cholecystokinin
    4. insulin
    5. glucagon
88.               ions are produced within the parietal cells and transported across the apical membrane via an active transporter while, at the same time,   moves across the apical membrane through ion channels.
    1. Hydrogen : chloride
    2. Bicarbonate : hydrogen
    3. Hydrogen : sodium
    4. Hydrogen : bicarbonate
    5. Bicarbonate : chloride
89. Which of the following is a gastric-phase stimulus for acid secretion?
    1. chewing and the act of swallowing
    2. the presence of fat and protein digestion products in the lumen of the stomach
    3. distension of the stomach and the act of swallowing
    4. distension of the stomach and the presence of protein digestion products in the lumen of the stomach
    5. chewing, swallowing, and the presence of protein digestion products in the lumen of the stomach
90. A person taking a histamine (H2) blocker or a proton pump inhibitor to relieve excess stomach acid production often finds a return of symptoms that is worse with a missed dose. Which statement about the effects these medications have on gastrin is FALSE?
    1. Decreased acid production inhibits inhibition of gastrin release into the bloodstream, thereby disrupting its negative feedback mechanism.
    2. Acid-blocking medications interrupt the negative feedback on gastrin release and are therefore self-limiting in their use.
    3. Acid blockers have no direct effect on gastrin, but inhibit acid production through other mechanisms.
    4. Return of symptoms by excess gastrin's influence on acid production stimulates further medication use, thereby leading to a chronic consumption.
    5. High circulating levels of gastrin accompany acid-blocking medication use and, if interrupted, a pronounced rebound effect of excess stomach acid ensues.

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91. In response to the presence of food within the duodenum, the increased release of what hormone is the predominant stimulus for an increase in enzyme secretion from the exocrine pancreas?
    1. insulin
    2. secretin
    3. glucose-dependent insulinotropic peptide
    4. gastrin
    5. cholecystokinin
92. In response to the presence of food within the duodenum, the increased release of what hormone will predominantly stimulate the increase of bicarbonate secretion from the exocrine pancreas?
    1. gastrin
    2. insulin
    3. secretin
    4. glucose-dependent insulinotropic peptide
    5. cholecystokinin
93. The secretion of cholecystokinin is predominantly regulated by which of the following?
    1. carbohydrate digestion products
    2. opening of the pyloric sphincter

93. 3. distention of the duodenum
    4. protein digestion products and fat presence in the duodenum
    5. acid and amino acid content of the chyme
94. The secretion of secretin is predominantly regulated by which of the following?
    1. distention of the duodenum
    2. acid content of the duodenum
    3. protein digestion products and fat
    4. carbohydrate digestion products
    5. opening of the pyloric sphincter
95. Which of the following are mechanisms by which cholecystokinin (CCK) facilitates digestion of fats?
    1. stimulation of bile secretion and contraction of the sphincter of Oddi
    2. stimulation of lipase secretion and gallbladder contraction
    3. stimulation of lipase and bile secretion
    4. stimulation of gallbladder contraction and relaxation of the sphincter of Oddi
    5. stimulation of bile secretion and liver contraction
96. What is the main hormone that stimulates bile secretion in the liver?
    1. glucagon
    2. secretin
    3. cholecystokinin
    4. insulin
    5. gastrin  16
97. In the intestine, the smooth muscle cell's
    1. contraction requires an action potential but its force is graded by the extent of neurotransmitter released.
    2. contraction requires an action potential and its force is therefore graded by the frequency of action potentials.
    3. contraction is stimulated by motor neurons.
    4. force of contraction is graded by the extent of depolarization for slow waves whether an action potential is generated or not.
    5. force of contraction is graded by the extent of depolarization for slow waves until an action potential is generated.

98. What causes peristalsis?
    1. contraction of both the circular muscle layer and longitudinal muscle in the proximal segment coupled with the relaxation of both the circular muscle layer and longitudinal muscle in the distal segment
    2. relaxation of the circular muscle layer and contraction of the longitudinal muscle in the proximal segment coupled with the relaxation of longitudinal muscle and contraction of the circular muscle in the distal segment
    3. relaxation of the circular muscle layer and contraction of the longitudinal muscle at the same segment
    4. contraction of the circular muscle layer and relaxation of the longitudinal muscle at the same segment
    5. contraction of the circular muscle layer and relaxation of the longitudinal muscle in the proximal segment coupled with the contraction of longitudinal muscle and relaxation of the circular muscle in the distal segment

99. What causes segmentation?
    1. contraction of longitudinal muscle at one intestinal segment coupled with its relaxation at adjoining segments
    2. contraction of the circular muscle at one intestinal segment coupled with its relaxation at adjoining segments
    3. contraction of the circular muscle at one intestinal segment coupled with contraction of the longitudinal muscle at adjoining segments

1. 4. relaxation of circular muscle layer and contraction of the longitudinal muscle at one segment coupled to the relaxation of longitudinal muscle and contraction of the circular muscle in the adjoining

segments

1. 5. contraction of both the circular and longitudinal layers of muscle at one segment coupled with the relaxation of both at adjoining segments

100. What does propelling food to the back of the mouth with the tongue initiate?

1. receptive relaxation
2. the swallowing reflex
3. the chewing reflex
4. bolus formation
5. peristalsis  17

101. What does entry of the bolus into the esophagus initiate by stimulating stretch receptors?

1. the swallowing reflex
2. the chewing reflex
3. peristalsis
4. bolus formation
5. receptive relaxation

102. What is the decrease in rugae folding within the stomach in advance of the arrival of a bolus of food called?

1. gastric expansion
2. receptive relaxation
3. gastric unfolding
4. esophageal reflex relaxation
5. peristaltic relaxation

103. The peristaltic waves of the stomach will result in if the pyloric sphincter is closed.

1. an inhibition of further waves
2. the mixing of the chyme
3. stimulation of hormone secretion from the duodenum
4. some of the chyme being forced into the duodenum even
5. the formation of a bolus

104. Which of the following describes events of the migrating motility complex in the stomach?

1. intense antral contractions accompanied by pyloric relaxation
2. mild fundic contractions accompanied by pyloric relaxation
3. mild antral contractions accompanied by pyloric relaxation
4. intense antral contractions accompanied by pyloric contraction
5. intense fundic contractions accompanied by pyloric contraction

105. Where does peristalsis occur?

1. esophagus only
2. stomach only
3. small intestine only
4. stomach and small intestine only
5. esophagus, stomach, and small intestine

106. Which of the following increases gastric motility?

1. distension of the stomach
2. distension of the intestines
3. increased osmolarity of duodenal contents
4. increased fat content in the lumen of the duodenum
5. cholecystokinin and secretin

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107. What is the function of segmentation in the small intestines?

1. propelling the chyme
2. mixing the chyme
3. releasing pancreatic juices
4. the opening of the pyloric valve
5. releasing bile from the gall bladder

108. What reflex protects the small intestine by inhibiting contractions while the intestines are injured or severely distended?

1. colonocolonic reflex
2. intestino-intestinal reflex
3. gastrocolic reflex
4. ileogastric reflex
5. gastroileal reflex

109. What reflex stimulates the motility of the ileum in response to the presence of chyme in the stomach?

1. gastroileal reflex
2. colonocolonic reflex
3. ileogastric reflex
4. gastrocolic reflex
5. intestino-intestinal reflex

110. What stimulates the defecation reflex?

1. pressure on the internal anal sphincter
2. increase in osmolarity of the rectum
3. distention of the descending colon
4. distention of the rectum
5. peristaltic contraction of the sigmoid colon

111. What is a mass movement?

1. a peristaltic-like wave in the large intestine that propels the contents toward the rectum
2. a segmentation-like wave in the large intestine that mixes the contents
3. another name for defecation
4. a segmentation-like wave in the large intestine that causes the elimination of contents as feces
5. a peristaltic-like wave in the large intestine that causes the elimination of contents as feces

112. What is the innermost layer of the gastrointestinal wall called?

1. myenteric plexus
2. muscularis externa
3. serosa
4. submucosa
5. mucosa  19

113. As the outermost layer of the gastrointestinal wall, which of the following secretes a lubricant to slide over other organs?

1. serosa
2. submucosa
3. muscularis externa
4. mucosa
5. myenteric plexus

114. What contains the muscularis mucosae?

1. mucosa
2. muscularis externa

3. submucosa
4. serosa
5. myenteric plexus

115. What structure contains enterocytes and the lamina propria?

1. myenteric plexus
2. mucosa
3. submucosa
4. serosa
5. muscularis externa

116. Which of the following contains the mucous membrane, but not the mesentery?

1. serosa
2. myenteric plexus
3. mucosa
4. muscularis externa
5. submucosa

117. Which contains the smooth muscle layers for peristalsis and segmentation?

1. myenteric plexus
2. serosa
3. muscularis externa
4. submucosa
5. mucosa

118. Which of the following contains the submucosal plexus?

1. myenteric plexus
2. serosa
3. submucosa
4. muscularis externa
5. mucosa  20

119. Where would the myenteric plexus be found?

1. lamina propria
2. submucosa
3. mucosa
4. muscularis externa
5. serosa

120. Which layer consists primarily of connective tissue which gives the gastrointestinal tract its distensibility and elasticity?

1. serosa
2. submucosa
3. muscularis externa
4. myenteric plexus
5. mucosa

121. Which of the following structures is continuous with the mesenteries?

1. muscularis externa
2. mucosa
3. serosa
4. myenteric plexus
5. submucosa

122. What sphincter is composed of smooth muscle between the anus and external environment?

1. upper esophageal sphincter
2. sphincter of Oddi
3. internal anal sphincter
4. external anal sphincter
5. lower esophageal sphincter

123. Which sphincter is composed of skeletal muscle between the anus and external environment?

1. internal anal sphincter
2. lower esophageal sphincter
3. external anal sphincter
4. upper esophageal sphincter
5. sphincter of Oddi

124. Which sphincter is composed of smooth muscle between the small and large intestines?

1. upper esophageal sphincter
2. sphincter of Oddi
3. ileocecal sphincter
4. lower esophageal sphincter
5. internal anal sphincter

21

125. Which sphincter is composed of smooth muscle between the ampulla of Vater and the duodenum?

1. pyloric sphincter
2. internal anal sphincter
3. ileocecal sphincter
4. sphincter of Oddi
5. lower esophageal sphincter

126. Which sphincter is composed of smooth muscle between the stomach and duodenum?

1. ileocecal sphincter
2. pyloric sphincter
3. internal anal sphincter
4. sphincter of Oddi
5. lower esophageal sphincter

127. Which sphincter is composed of smooth muscle between the esophagus and stomach?

1. sphincter of Oddi
2. lower esophageal sphincter
3. internal anal sphincter
4. upper esophageal sphincter
5. pyloric sphincter

128. Which sphincter is composed of skeletal muscle between the pharynx and esophagus?

1. upper esophageal sphincter
2. pyloric sphincter
3. external anal sphincter
4. sphincter of Oddi
5. lower esophageal sphincter

129. Where is the acid in the stomach produced?

A) neck cell B) acinar cell C) chief cell D) G cell E) parietal cell

130. Which cell secretes gastrin into the bloodstream?

A) G cell B) acinar cell C) neck cell D) chief cell E) parietal cell

131. Intrinsic factor is produced where?

A) parietal cell B) neck cell C) acinar cell D) chief cell E) G cell

132. Mucus is secreted by which cell?

A) neck cell B) acinar cell C) G cell D) parietal cell E) chief cell

22

133. Which cell secretes pepsinogen?

A) parietal cell B) acinar cell C) chief cell D) neck cell E) G cell

134. Rugae create greater surface area in what organ?

1. stomach
2. pancreas
3. large intestine
4. liver
5. small intestine

135. Crypts of Lieberkühn are found in which organ?

1. liver
2. stomach
3. pancreas
4. small intestine
5. large intestine

136. Where are the gastric pits found?

1. stomach
2. pancreas
3. liver
4. large intestine
5. small intestine

137. The brush border is located in which organ?

1. stomach
2. liver
3. large intestine
4. pancreas
5. small intestine

138. Sinusoids are openings where blood flows through and exchange takes place found in which of the following?

1. large intestine
2. pancreas
3. liver
4. small intestine
5. stomach  23

139. Islets of Langerhans are highly vascularized bits of endocrine tissue found where?

1. small intestine
2. pancreas
3. stomach
4. liver
5. large intestine

140. Acini are located in which of the following?

1. liver
2. large intestine

3. pancreas
4. small intestine
5. stomach

141. Bile canaliculi are located in which organ?

1. small intestine
2. large intestine
3. pancreas
4. stomach
5. liver

142. Which enzyme catalyzes reactions with polysaccharides?

1. chymotrypsin
2. lipase
3. glucoamylase
4. sucrase
5. amylase

143. Sucrose is the substrate for which enzyme?

1. amylase
2. glucoamylase
3. chymotrypsin
4. sucrase
5. lipase

144. Straight-chain glucose polymers would require which enzyme for their catabolism?

1. lipase
2. dextrinase
3. chymotrypsin
4. sucrase
5. amylase  24

145. Proteins are cleaved by which enzyme?

1. dextrinase
2. chymotrypsin
3. amylase
4. sucrase
5. lipase

146. Lipids are disassembled by which of the following?

1. glucoamylase
2. lipase
3. chymotrypsin
4. sucrase
5. amylase

147. Which hormone stimulates gastric secretion and motility?

1. gastrin
2. secretin
3. inhibin
4. glucose-dependent insulinotropic peptide
5. cholecystokinin

148. Which hormone primarily simulates pancreatic bicarbonate secretion (and enzyme secretion, to a lesser extent)?

1. glucose-dependent insulinotropic peptide
2. gastrin
3. motilin
4. secretin
5. cholecystokinin

149. Which hormone stimulates gall bladder contraction?

1. cholecystokinin
2. secretin
3. motilin
4. glucose-dependent insulinotropic peptide
5. gastrin

150. What is the predominant hormone to inhibit gastric secretion and motility in response to distension of the duodenum?

1. gastrin
2. cholecystokinin
3. motilin
4. glucose-dependent insulinotropic peptide
5. secretin  25

151. Which of the following stimulates the relaxation of the sphincter of Oddi?

1. glucose-dependent insulinotropic peptide
2. cholecystokinin
3. gastrin
4. secretin
5. motilin

152. Which of the following structures of the gastrointestinal tract has a wall structure that differs from others?

1. ileum
2. upper third of esophagus
3. mouth
4. external-most portion of anus
5. pharynx

153. What is the correct order of the three layers of the mucosa, from innermost to outermost?

1. mucosa, submucosa, serosa
2. mucous membrane, lamina propria, muscularis mucosae
3. muscularis mucosa, submucosa, muscularis externa
4. mucous membrane, lamina propria, basement membrane
5. serosa, submucosa, mucosa

154. In what subdivision of the four layers of the GI tract are Peyer's patches located?

1. myenteric plexus of the muscularis externa
2. submucosa of the mucosa
3. mucous membrane of the serosa
4. lamina propria of the serosa
5. lamina propria of the mucosa

155. What is the portion of the enteric nervous system located within the muscularis mucosa called?

1. myenteric (Auerbach's) plexus
2. submucosal (Meissner's) plexus
3. bulbous (Ruffini's) corpuscle
4. lamellar (Pacinian) corpuscle
5. intrinsic nervous system

156. The G cells that line the lumen of the stomach are responsible for the secretion of what compound?

1. pepsinogen
2. ghrelin
3. intrinsic factor
4. HCl
5. gastrin  26

157. The stomach's lining is protected from the acidic contents of the lumen by a layer of mucus and bicarbonate called what?

1. gastric mucosal barrier
2. prandial succus gastricus
3. PGE2 inducement
4. glycocalyx
5. succus entericus

158. What are the two sources of bicarbonate secreted into the lumen of the small intestine?

1. secretin and inhibin
2. secretin and glucose-dependent insulinotropic peptide
3. exocrine pancreas and secretory cells in the crypts of Lieberkühn
4. bile and exocrine pancreas
5. both exocrine and endocrine pancreas

159. Microvilli of epithelial cells in the small intestine make up what structure?

1. mucociliary ladder
2. villi
3. lacteal
4. brush border
5. succus entericus

160. What blood vessel supplies the liver with oxygenated blood?

1. hepatic artery
2. inferior gastric
3. superior mesenteric artery
4. hepatic portal
5. sinusoidal system

161. All of the segments of the colon are specialized for absorbing water and ions EXCEPT the

1. descending colon.
2. sigmoidal colon.
3. transverse colon.
4. cecum.
5. ascending colon.

162. What is the process where fecal material is removed from the body called?

A) secretion B) excretion C) micturition D) defecation E) elimination

163. All of the following are branches of vessels found at the corners of the liver lobule EXCEPT the

A) bile duct. B) hepatic artery.

C) hepatic duct. D) hepatic portal vein.

27

164. What are macrophages in the liver called?

1. histiocytes
2. giant cells

3. sinusoidal lining cells
4. sideroblasts
5. Kupffer cells

165. Where are the enzymes responsible for degrading disaccharides and limit dextrins located?

1. endocrine pancreas
2. pylorus
3. ampulla of Vater
4. brush border of the small intestine
5. exocrine pancreas

166. What is a glucose polymer found in plant products that cannot be degraded within the digestive tract of humans?

1. fructose
2. chitin
3. pectin
4. cellulose acetate
5. cellulose

167. What is the process whereby bile salts breakdown fat globules into smaller droplets?

1. lipolysis
2. saponification
3. digestion
4. emulsification
5. esterification

168. Monoglycerides and free fatty acids that are not immediately transported into lumenal enterocytes aggregate into what type form in the lumen of the small intestines?

1. HDLs
2. phospholipid bilayer
3. micelles
4. chylomicra
5. VLDLs

169. For calcium to be absorbed, it must bind to a hormone-regulated brush border protein called what?

1. calmodulin
2. calcitrol
3. calcium-binding protein (calbindin)
4. vitamin D
5. calciferol  28

170. Enterocytes secrete what protein into the lumen of the small intestine to facilitate the absorption of iron?

1. hemosiderin
2. transferrin
3. ferroxidase
4. ferritin
5. siderophores

171. Macrophages secrete what substance that may contribute to insulin resistance?

1. insulin-like growth factor (IGF-1)
2. casein
3. resistin
4. glucagon
5. glucose

172. What are the spontaneous graded potentials that occur in smooth muscle cells of the digestive tract called?

1. basic electrical rhythm (BER)
2. segmentation
3. slow waves
4. peristalsis
5. intestinal phase

173. All of the following are factors that affect the rate of gastric emptying EXCEPT

1. amount of peptides in the duodenum.
2. force of gastric contraction.
3. composition of the chyme.
4. temperature of the chyme.
5. volume of the chyme in the stomach.

174. Intense contractions of the antrum accompanied by relaxation of the pyloric sphincter that function to sweep the stomach clean of its contents are called the

A) receptive relaxation. B) peristalsis.

C) migrating motility complex. D) segmentation.

175. The function of each region of the digestive tract is dependent upon its structure. Describe the general structures of the digestive tract wall, including the unique cells within the structures that provide specialized functions.
176. The digestive tract is much more than a hollow tube that absorbs nutrients. Accessory glands play an essential role in the process of digestion. Describe the structure of the accessory glands, their functions, and the molecules they secrete.
177. The primary function of the gastrointestinal tract is digestion and absorption of nutrients. Describe the process of digestion and absorption of carbohydrates, including the enzymes and transporters involved in this process.
178. The primary function of the gastrointestinal tract is digestion and absorption of nutrients. Describe the process of digestion and absorption of proteins, including the enzymes and transporters involved in this process.
179. The primary function of the gastrointestinal tract is digestion and absorption of nutrients. Describe the process of digestion and absorption of fats, including the enzymes and transporters involved in this process.
180. Regulation of the gastrointestinal tract involves an interaction between hormones and neural inputs. Describe the role of the four hormones that regulate digestion.
181. Regulation of the gastrointestinal tract involves an interaction between hormones and neural inputs. Describe the role of the nervous system in the regulation of digestion, including the receptors involved. (Do not include motility in this answer.)
182. Discuss the regulation of gastrointestinal motility, including the mechanisms that control the electrical activity of the smooth muscle cell wall. (Do not include the reflexes in this answer.)
183. A number of reflexes play an important role in regulating motility through the digestive system. Describe each of the reflexes that are involved in gastrointestinal tract motility.
184. Bile is synthesized in the (liver / gallbladder) and stored in the (liver / gallbladder).
185. Stimulation of chemoreceptors and mechanoreceptors by the presence of food in the lumen of the digestive tract (enhances / suppresses) hunger.
186. The act of chewing and swallowing increases (parasympathetic activity / sympathetic activity), which