York University - KINE 4020

Chapter 3 Digestion, Absorption, and Transport

MULTIPLE CHOICE

1)The process by which food is broken down into absorbable components is called which of the follow- ing?

1. 1. digestion
   2. absorption
   3. secretion
   4. mastication

2. What is mastication?
   1. the act of chewing
   2. the act of swallowing
   3. the wave-like contraction of the intestines
   4. the wave-like contraction of the esophagus

3. Which of the following parts is the lumen of the GI tract?
   1. the epiglottis
   2. the capillaries
   3. the inner space
   4. the mucosal surface

4. In what organ does the digestion process begin?
   1. mouth
   2. stomach
   3. duodenum
   4. jejunum-ileum

5. What is umami?
   1. the flavour of monosodium glutamate
   2. the opening between the duodenum and jejunum
   3. the intestinal enzyme that hydrolyzes fish proteins
   4. an intestinal enzyme that hydrolyzes dietary nucleic acids

6. About how many more times sensitive is the sense of smell compared with the sense of taste?
   1. 2 times
   2. 10 times
   3. 100s of times

1. 4. 1000s of times

7. Which of the following is a basic taste sensation?
   1. hot
   2. cold
   3. sugary
   4. bitter

8. The food flavour enhancer monosodium glutamate is believed by some scientists to promote a unique taste sensation known by which of the following terms.
   1. salinos
   2. umami
   3. chymos
   4. glutami

9. Which of the following best describes the anatomy of the gastrointestinal tract?
   1. a vat-like vessel
   2. a rigid, solid tunnel
   3. a flexible muscular tube
   4. a firm, duct-like channel

10. Which of the following is a specific sphincter muscle?
    1. longitudinal
    2. cardiac
    3. duodenal
    4. diaphragmatic

11. Where is the epiglottis located?
    1. throat
    2. bile duct
    3. pancreatic duct
    4. lower esophagus

12. What structure separates the colon from the small intestine?
    1. pylorus
    2. ileocecal valve
    3. gastric retainer
    4. rectal sphincter

13. What structure controls the release of material from the stomach to the small intestine?
    1. ileocecal valve
    2. pyloric sphincter
    3. diaphragmatic valve
    4. esophageal sphincter

14. What part of the GI tract prevents a person from choking while swallowing?
    1. mouth
    2. epiglottis
    3. pyloric sphincter
    4. upper esophageal sphincter

15. What structure functions to prevent entrance of food into the trachea?
    1. tongue
    2. epiglottis
    3. cardiac sphincter
    4. trachea sphincter

16. Which of the following is a function of the appendix?
    1. It ferments fibre.
    2. It stores lymph cells.
    3. It slows down peristalsis.
    4. It stores preformed stools.

17. What is a bolus?
    1. enzyme that hydrolyzes starch
    2. portion of food swallowed at one time
    3. device used to analyze the contents of the stomach
    4. sphincter muscle separating the stomach from the small intestine

18. A bolus is conducted past the diaphragm through which of the following parts.
    1. epiglottis
    2. stomach
    3. esophagus
    4. large intestine

19. Which of these is one function of the pyloric sphincter?
    1. secrete acid into the stomach
    2. secrete hormones into the stomach
    3. prevent the contents of the small intestine from backing up into the stomach
    4. prevent the contents of the small intestine from emptying too quickly into the colon

20. Which of the following structures controls the passage of material from the small intestine to the large intestine?
    1. pyloric valve
    2. ileocecal valve
    3. colonic sphincter
    4. jejunal sphincter

21. What is the primary function of the rectum?
    1. control functioning of the colon
    2. absorb minerals from waste materials
    3. store waste materials prior to evacuation
    4. absorb excess water from waste materials

22. Into what region of the intestinal tract does the stomach empty?
    1. ileum
    2. cecum
    3. jejunum
    4. duodenum

23. After swallowing, in what order does food pass through the regions of the GI tract?
    1. jejunum, duodenum, colon, ileum, rectum
    2. jejunum, ileum, duodenum, rectum, colon
    3. stomach, duodenum, jejunum, ileum, colon
    4. stomach, jejunum, duodenum, colon, ileum

24. Which of the following is a description of chyme?
    1. the semisolid mass of undigested food which passes through the ileocecal valve
    2. a semiliquid mass of partially digested food released by the stomach into the small intest- ine
    3. the mixture of pancreatic juices containing enzymes for digestion of the macronutrients
    4. a thick, viscous material synthesized by mucosal cells for protection against digestive juices

25. What is the name given to partially digested food in the stomach?
    1. chyme
    2. liquid food
    3. gastric mucus
    4. semiliquid mass

26. What is meant by the term “motility” in reference to the GI tract?
    1. the efficiency of lymph transport
    2. the ability of the GI tract muscles to move
    3. the speed of gastric digestive juice release
    4. the speed of pancreatic digestive juice release

27. Which of the following best defines peristalsis?
    1. It is the static or quiet period between meals when the GI tract is empty.
    2. It is the constant rate of contraction along the GI tract when food is present.
    3. It is contraction of parallel and circular muscles found in the walls of the intestines but not the stomach.
    4. It is wavelike muscular contractions resulting from alternate tightening and relaxing of cir- cular and longitudinal muscles of the GI tract.

28. Which of the following best describes the muscular actions of digestion?
    1. Peristalsis begins in the stomach upon the initiation of the swallowing reflex.
    2. Contraction and relaxation along the jejunum is enhanced by a third layer of diagonal muscles.
    3. Segmentation along the intestines allows momentary reversal of the movement of intest- inal contents.
    4. Relaxation of the rectal sphincter muscles prevents the continuous elimination of stool.

29. During the process of digestion, at what point does the stomach begin to release chyme?
    1. when the fluid to solid ratio in chyme is 3 to 1
    2. when the chyme is liquefied
    3. within 15 minutes of gastrin release
    4. within 5–10 minutes of starting a meal

30. Which of the following GI tract organs has the strongest muscles?
    1. stomach
    2. small intestine

1. 3. large intestine
   4. cardiac sphincter

31. Which of the following is a function of sphincter muscles?
    1. control peristalsis
    2. grind large food particles
    3. secrete digestive juices into the GI tract
    4. control the passage of food through the GI tract

32. The lower esophageal sphincter is also known as which of the following?
    1. reflux restrainer
    2. cardiac sphincter
    3. perihepatic control valve
    4. reverse peristalsis inhibitor

33. What is reflux?
    1. hard, dry, stools
    2. backward flow of chyme
    3. soft, poorly formed stools
    4. the mixture of bile and pancreatic juice

34. What types of enzymes are responsible for hydrolyzing the proteins in foods?
    1. lipases
    2. salivases
    3. proteases
    4. carbohydrases

35. Which of the following organs are directly involved in the digestion of protein?
    1. Stomach, salivary glands and pancreas
    2. Stomach, pancreas and colon
    3. Stomach, pancreas and jejunum.
    4. Stomach, gallbladder and ileum.

36. What is the function of mucus in the stomach?
    1. emulsify fats
    2. neutralize stomach acid
    3. activate pepsinogen to pepsin
    4. protect stomach cells from gastric juices

37. What is a function of hydrochloric acid in the stomach?
    1. It absorbs water.
    2. It inhibits peristalsis.
    3. It neutralizes the alkaline food mass.
    4. It creates an optimum pH.

38. Which of the following best describes the normal pH of the stomach?
    1. very acidic
    2. slightly acidic
    3. neutral
    4. slightly alkaline

39. Why is there little or no digestion of starch in the stomach?
    1. Mucus inhibits starch breakdown.
    2. Stomach enzymes are dysfunctional.
    3. Starch has already been adequately digested by salivary enzymes.
    4. Salivary enzymes do not work in an acid environment.

40. What is the fate of any enzymes that are present in the foods we eat?
    1. hydrolyzed in the GI tract
    2. absorbed intact by the stomach
    3. absorbed intact by the small intestine
    4. passed through the GI tract and excreted in the stool

41. What substance protects the stomach lining from damage due to digestive juices?
    1. water
    2. mucus
    3. pepsinogen
    4. dietary fats

42. Which is an example of a role of hydrochloric acid in the gastrointestinal tract?
    1. It kills bacteri
    2. It activates pancreatic enzymes.
    3. It raises the pH of chyme.
    4. It promotes hydrolysis of dietary carbohydrate.

43. Which of these parts of the GI tract contains highly acidic digestive juices?
    1. colon
    2. ileum
    3. stomach
    4. duodenum

44. The usual pH of gastric juice is approximately which of the following values?
    1. 2
    2. 4
    3. 6
    4. 7

45. Which of these is an important function of mucus?
    1. help solubilize bile
    2. stabilize pancreatic enzymes
    3. enhance absorption of vitamin B12
    4. protect the stomach walls from digestion

46. After a portion of food is chewed and swallowed, what happens to the salivary amylase in the stom- ach?
    1. It is inactivated by gastric juice.
    2. It continues to hydrolyze starches.
    3. It binds to pepsin and catalyzes proteolytic activity.
    4. It passes into the duodenum where the alkaline pH stimulates carbohydrase activity.

47. Which of the following body organs secretes digestive enzymes?
    1. esophagus
    2. gastric glands
    3. liver
    4. endocrine glands

48. The process by which bile acts on fat so enzymes can attack the fat is known as which of the follow- ing?
    1. condensation
    2. emulsification
    3. enzymification
    4. phosphorylation

49. Which of the following is is digested by pancreatic juice?
    1. fats
    2. fibre
    3. zymogens
    4. insulin

50. Which of the following is a component of pancreatic juice?
    1. bile
    2. HCl
    3. lipase
    4. emulsifier

51. Your cousin Miguel is extolling the virtues of his new dietary supplement. He says that it contains en- zymes that will make him healthier, and he asks for your opinion. You tell him that the enzymes
    1. will increase the digestibility of the foods he eats
    2. could likely interfere with the enzymes secreted by his pancreas
    3. could likely overload his gastrointestinal tract and lead to diarrhea
    4. are proteins and proteins are destroyed in the gastrointestinal tract

52. A solution with a pH of 7 is how many times more alkaline than a solution with a pH of 6?
    1. 1 time
    2. 5 times
    3. 10 times
    4. 100 times

53. How does bicarbonate contribute to the digestive process?
    1. It raises the pH of chyme
    2. It prevents reflux of of chyme (heartburn).
    3. It emulsifies lipids in the duodenum.
    4. It breaks down starch to simple sugars.

54. After the pancreatic juices have mixed with chyme in the small intestine, which of the following de- scribes the pH of the resulting mixture?
    1. very acidic
    2. moderately acidic
    3. strongly alkaline
    4. approximately neutral

55. Which of the following is produced by bacterial fermentation of certain fibres in the colon?
    1. cholesterol
    2. minerals
    3. secretin
    4. small fat fragments

56. What is one function of the gallbladder?
    1. store bile
    2. produce bile
    3. reabsorb water and salts
    4. perform enzymatic digestion

57. An example of an important function of the colon would be its absorption of which of the following substances?
    1. bile
    2. fats
    3. salts
    4. hormones

58. Which of the following would be the largest component of stools?
    1. fats
    2. fibre
    3. pesticide and heavy metal residues
    4. peptides

59. Which of the following classes of nutrients requires the least amount of digestion?
    1. lipids
    2. proteins
    3. vitamins
    4. carbohydrates

60. Which of the following nutrients requires the least amount of digestion?
    1. starch
    2. calcium
    3. animal fats
    4. animal proteins

61. Which of the following is generally NOT digested but does stimulate intestinal muscle contractions?
    1. bile
    2. fibre
    3. starch
    4. amylase

62. Which of the following is the most important function of fibre in digestive health?
    1. It provides energy (Calories) through bacterial fermentation in the colon.
    2. It increases fecal bulk and stimulates intestinal muscle contractions.
    3. It supports the elimination of cholesterol in stools.
    4. It helps rid the body of contaminants.

63. What is the function of bile?
    1. emulsify fats
    2. initiate digestion of protein
    3. enhance absorption of complex carbohydrates
    4. protect the stomach and small intestine from the action of hydrochloric acid

64. Nancy has stones that are blocking bile release from her gallbladder. What is likely to be the main re- sponse to her problem?
    1. impaired fat digestion
    2. impaired carbohydrate digestion
    3. impaired protein digestion
    4. impaired CCK release

65. Which of the following mechanisms is an important function of the intestinal villi crypts?
    1. synthesis of chylomicrons
    2. secretion of juices into the small intestine
    3. synthesis of fragments of fat for use by the colon
    4. transport of fat-soluble nutrients into the circulation

66. What is the name of the projections on the inner surface of the small intestine?
    1. villi
    2. cilia
    3. mesenteric vessels
    4. vascular projectiles

67. Which of the following is a function of the intestinal microvilli?
    1. secretion of bile salts
    2. secretion of digestive acid
    3. transport of nutrient molecules
    4. transport of pancreatic enzymes

68. Which of the following is the primary site for absorption of nutrients?
    1. crypt
    2. villus
    3. microvillus
    4. macrovillus

69. Which of the following are found on the microvilli and function to break apart small nutrients into the final products of digestion?
    1. mucus
    2. micelles
    3. enzymes
    4. hormones

70. Which mechanism directly accounts for the absorption of some nutrients by intestinal cells?
    1. dilution
    2. transmigration
    3. active transport
    4. facilitated diversion

71. How does the concept of surface area most relate to the absorption of nutrients?
    1. The presence of fibre in a meal expands the intestinal lumen and thereby the surface area for nutrient absorption.
    2. The surface area of nutrient molecules if the main determinant of the process of absorp- tion.
    3. Large numbers of villi and microvilli in the small intestine increase the surface area for nutrient absorption.
    4. The surface area of pancreatic enzymes is a key factor in their digestive capacity.

72. Which of the following is a significant property of dietary fibre?
    1. inhibition of protease activity
    2. promotion of water retention of stools
    3. inhibition of large intestinal contractions
    4. promotion of vitamin excretion in stools

73. To assist the process of digestion and absorption, it is usually best to do which of the following?
    1. Eat several snacks per day so the system is not overwhelmed.
    2. Combine different food types to enhance the absorption process.
    3. Avoid eating meat and fruit at the same meal to prevent competition.
    4. Take enzyme pills or powder periodically so the system can rest and rejuvenate.

74. When nutrients are transported from intestinal epithelial cells to the vascular system, what organ is first to receive them?
    1. liver
    2. heart
    3. lungs
    4. kidneys

75. Which of the following products of digestion is released directly into the bloodstream?
    1. chylomicrons
    2. minerals
    3. polypeptides
    4. soluble fibre

76. Exchange of oxygen, nutrients, and waste materials takes place across the walls of which of the fol- lowing small vessels?
    1. ducts
    2. venules
    3. arterioles
    4. capillaries

77. What vessel carries blood from the liver to the heart?
    1. aorta
    2. hepatic vein
    3. thoracic duct
    4. hepatic portal vein

78. The hepatic portal vein empties into which organ?
    1. liver
    2. heart
    3. pancreas
    4. lung

79. When alcohol and barbiturates are ingested, they are absorbed from the gastrointestinal tract and trans- ported first to which of the following organs?
    1. liver
    2. heart
    3. spleen
    4. kidneys

80. Which of the following conducts lymph into the vascular system?
    1. villi
    2. mesentery
    3. subclavian vein
    4. common bile duct

81. What are lacteals?
    1. gastric secretory cells
    2. products of milk digestion
    3. intestinal lymphatic vessels
    4. products of colonic fermentation

82. Which distinguishes the lymphatic system from the vascular system?
    1. The lymphatic system carries fats from the intestines to the liver before they can enter the vasculature.
    2. The lymphatic system circulates via a one-way pump at the junction to the subclavian vein.
    3. The lymphatic system takes fats from the intestines to the bloodstream, initially bypassing the liver.
    4. The lymphatic system transports fat-soluble and water-soluble vitamins to the vascular system via the thoracic duct.

83. Which of these is the first major organ to receive nutrients that are absorbed into the lymph?
    1. liver
    2. heart
    3. spleen
    4. pancreas

84. Immediately after absorption, what circulatory system carries the fat-soluble vitamins and large fats?
    1. vascular system
    2. mesenteric system

1. 3. lymphatic system
   4. enterohepatic system

85. The living bacteria found in yogurt are known as what microorganisms?
    1. probiotics
    2. prebiotics
    3. postbiotics
    4. zymobiotics

86. Microorganisms in food that are viable when consumed and that are beneficial to health are known by which of the following terms?
    1. probiotics
    2. prebiotics
    3. postbiotics
    4. zymobiotics

87. When consumed on a regular basis, which of the following foods promotes healthful changes of the microflora of the GI tract?
    1. fish
    2. yogurt
    3. poultry
    4. iron-rich foods

88. The intestinal flora are comprised primarily of which of the following?
    1. parasites
    2. bacteria
    3. fibre
    4. probiotics

89. What is the primary role of the normal, thriving, intestinal, bacterial population?
    1. help degrade meat and dairy proteins
    2. help prevent infectious bacteria from attacking the system
    3. synthesize vitamin D, which can be absorbed into the body
    4. synthesize several amino acids which can be absorbed into the body

90. Which of the following is known to be produced by small intestinal bacteria?
    1. mucus
    2. chyme

1. 3. glucose
   4. vitamins

91. The maintenance of the body’s constant internal conditions is guided by which principle?
    1. homeostasis
    2. regularity
    3. bioregulation
    4. metabolic balance

92. Which 2 systems coordinate all digestive/absorptive processes?
    1. enzyme and thoracic systems
    2. portal and lymphatic systems
    3. nervous and endocrine systems
    4. transport and circulatory systems

93. What is the normal pH of stomach juice? a.      0.25–0.50

b.   1.5–1.7

c.   7.0–7.5

d. 9.5–9.75

94. Which of the following hormones regulates the pH of the stomach?
    1. gastrin
    2. insulin
    3. secretin
    4. cholecystokinin

95. Which of the following substances functions to control the release of hydrochloric acid to prevent ex- cessive acidity?
    1. fibre
    2. gastrin
    3. secretin
    4. bicarbonate

96. Which of the following substances stimulates the pancreas to release bicarbonate-rich juice?
    1. gastrin
    2. secretin
    3. glucagon