Chapter 3 – Digestion, Absorption, and Transport
MULTIPLE CHOICE
1. The process by which food is broken down into absorbable components is called ____.
a.
digestion
b.
absorption
c.
excretion
d.
mastication
e.
adsorption
2. What is umami?
a.
The flavor of monosodium glutamate
b.
The opening between the duodenum and jejunum
c.
The intestinal enzyme that hydrolyzes fish proteins
d.
An intestinal enzyme that hydrolyzes dietary nucleic acids
e.
A flavor that combines sweet and sour
3. Taste buds ____.
a.
react only with particles in solution
b.
are located throughout the oral cavity
c.
produce amylase but not pepsin or lipase
d.
can individually sense only one of the basic taste sensations at a time
e.
are located only on the tip of the tongue
4. Where is the epiglottis located?
a.
Throat
b.
Bile duct
c.
Pancreatic duct
d.
Lower esophagus
e.
At the outlet of the stomach
5. What part of the GI tract prevents a person from choking while swallowing?
a.
Mouth
b.
Epiglottis
c.
Pyloric sphincter
d.
Upper esophageal sphincter
e.
Chyme
6. What structure functions to prevent entrance of food into the trachea?
a.
Tongue
b.
Epiglottis
c.
Cardiac sphincter
d.
Trachea sphincter
e.
Upper esophageal sphincter
7. Which action is characteristic of the appendix?
a.
It ferments fiber.
b.
It stores lymph cells.
c.
It slows down peristalsis.
d.
It stores preformed stools.
e.
It assists in the formation of T-cells.
8. What is a bolus?
a.
An enzyme that hydrolyzes starch
b.
A portion of food swallowed at one time
c.
A device used to analyze the contents of the stomach
d.
A sphincter muscle separating the stomach from the small intestine
e.
A food item that has passed through the small intestine into the colon
9. One function of the pyloric sphincter is to ____.
a.
secretes acid into the stomach
b.
secretes hormones into the stomach
c.
prevents the contents of the small intestine from backing up into the stomach
d.
prevents the contents of the small intestine from emptying too quickly into the colon
e.
initiates peristalsis
10. Chyme can best be described as ____.
a.
the semisolid mass of undigested food that passes through the ileocecal valve.
b.
a semiliquid mass of partially digested food released by the stomach into the small
intestine.
c.
the mixture of pancreatic juices containing enzymes for digestion of the macronutrients.
d.
a thick, viscous material synthesized by mucosal cells for protection against digestive
juices.
e.
chewed food combined with saliva that has passed from the esophagus into the stomach.
11. The primary function of the rectum is to ____.
a.
control functioning of the colon
b.
absorb minerals from waste materials
c.
store waste materials prior to evacuation
d.
absorb excess water from waste materials
e.
store digestive hormones until they are needed
12. What is the name given to partially digested food in the stomach?
a.
Chyme
b.
Liquid food
c.
Gastric mucus
d.
Semiliquid mass
e.
Bolus
13. What structure separates the colon from the small intestine?
a.
Pylorus
b.
Ileocecal valve
c.
Gastric retainer
d.
Rectal sphincter
e.
Lower sphincter
14. Which of the following is a feature of peristalsis?
a.
It occurs when longitudinal muscles oppose the action of transverse muscles.
b.
Its rate is consistent throughout the GI tract.
c.
It occurs at powerful levels in the small intestine but not at all in the colon.
d.
It is caused by alternate tightening and relaxing of circular and longitudinal muscles.
e.
It may occur unpredictably but is typically in response to a full stomach.
15. What structure controls the release of material from the stomach to the small intestine?
a.
Ileocecal valve
b.
Pyloric sphincter
c.
Diaphragmatic valve
d.
Esophageal sphincter
e.
Hepatic portal valve
16. One function of sphincter muscles is to ____.
a.
control peristalsis
b.
grind large food particles
c.
secrete digestive juices into the GI tract
d.
control the passage of food through the GI tract
e.
trigger hormone release
17. What structure prevents reflux of stomach contents?
a.
Pepsinogen
b.
Gastric mucosa
c.
Upper esophageal sphincter
d.
Lower esophageal sphincter
e.
Duodenum
18. What is the function of mucus in the stomach?
a.
It emulsifies fats.
b.
It neutralizes stomach acid.
c.
It activates pepsinogen to pepsin.
d.
It protects stomach cells from gastric juices.
e.
It absorbs essential nutrients.
19. What is a function of hydrochloric acid in the stomach?
a.
It absorbs water.
b.
It inhibits peristalsis.
c.
It neutralizes the food mass.
d.
It creates an optimum acidity.
e.
It prevents relaxation of the lower esophageal sphincter.
20. What best describes the normal pH of the stomach?
a.
Very acidic
b.
Slightly acidic
c.
Neutral
d.
Slightly alkaline
e.
Very alkaline
21. What substance protects the stomach lining from damage due to digestive juices?
a.
Water
b.
Mucus
c.
Pepsinogen
d.
Dietary fats
e.
Gastrin
22. Which part of the GI tract contains highly acidic digestive juices?
a.
Colon
b.
Ileum
c.
Stomach
d.
Duodenum
e.
Rectum
23. One important function of mucus is to ____.
a.
help solubilize bile
b.
stabilize pancreatic enzymes
c.
enhance absorption of vitamin B12
d.
protect the stomach walls from digestion
e.
facilitate peristalsis
24. The process by which bile acts on fat so that enzymes can attack the fat is known as ____.
a.
condensation
b.
emulsification
c.
enzymification
d.
phosphorylation
e.
inhibition
25. The purpose of bicarbonate in the digestive process is to ____.
a.
raise the pH of chime
b.
lower the pH of chime
c.
hydrolyze large peptides
d.
increase peristalsis
e.
reduce risk of vomiting
26. After the pancreatic juices have mixed with chyme in the small intestine, which of the following
describes the pH of the resulting mixture?
a.
Very acidic
b.
Moderately acidic
c.
Approximately neutral
d.
Moderately alkaline
e.
Very alkaline
27. One function of the gallbladder is to ____.
a.
store bile
b.
produce bile
c.
reabsorb water and salts
d.
perform enzymatic digestion
e.
Removes toxins from the blood
28. Which class of nutrients requires the least amount of digestion?
a.
Lipids
b.
Proteins
c.
Vitamins
d.
Simple carbohydrates
e.
Complex carbohydrates
29. What is the function of bile?
a.
It emulsifies fats.
b.
It initiates digestion of protein.
c.
It enhances absorption of complex carbohydrates.
d.
It protects the stomach and small intestine from the action of hydrochloric acid.
e.
It stimulates the absorption of vitamins and minerals.
30. What is an important function of the intestinal villi crypts?
a.
Synthesis of chylomicrons
b.
Secretion of juices into the small intestine
c.
Synthesis of fragments of fat for use by the colon
d.
Transport of fat-soluble nutrients into the circulation
e.
Storage of bile
31. What is the name of the projections on the inner surface of the small intestine?
a.
Villi
b.
Cilia
c.
Mesenteric vessels
d.
Vascular projectiles
e.
Mitochondria
32. What is a function of the intestinal microvilli?
a.
Secretion of bile salts
b.
Secretion of digestive acid
c.
Transport of nutrient molecules
d.
Transport of pancreatic enzymes
e.
Stimulation of peristalsis
33. What is the primary site for absorption of nutrients?
a.
Crypt
b.
Villus
c.
Microvillus
d.
Macrovillus
e.
Goblet cells
34. To assist the process of digestion and absorption, it is usually best to ____.
a.
eat several snacks per day so the system is not overwhelmed
b.
combine different food types to enhance the absorption process
c.
avoid eating meat and fruit at the same meal to prevent competition
d.
take enzyme pills or powder periodically so the system can rest and rejuvenate
e.
eat only one type of food at each meal in order to avoid overstimulation of acid
35. When nutrients are transported from intestinal epithelial cells to the vascular system, what organ is
first to receive them?
a.
Liver
b.
Heart
c.
Lungs
d.
Kidneys
e.
Gallbladder
36. What vessel carries blood from the liver to the heart?
a.
Aorta
b.
Hepatic vein
c.
Thoracic duct
d.
Hepatic portal vein
e.
Hepatic artery
37. The hepatic portal vein empties into the ____.
a.
liver
b.
heart
c.
pancreas
d.
hepatic vein
e.
spleen
38. Exchange of oxygen, nutrients, and waste materials takes place across the walls of small vessels called
____.
a.
ducts
b.
venules
c.
arterioles
d.
capillaries
e.
lymphatics
39. What is the most metabolically active organ?
a.
Liver
b.
Spleen
c.
Stomach
d.
Pancreas
e.
Brain
40. Which vehicle conducts lymph into the vascular system?
a.
Villi
b.
Mesentery
c.
Subclavian vein
d.
Common bile duct
e.
Thoracic duct
41. What is the first major organ to receive nutrients that are absorbed into the lymph?
a.
Liver
b.
Heart
c.
Spleen
d.
Pancreas
e.
Gallbladder
42. What is the general composition of lymph?
a.
A light-red fluid that stores fat-soluble vitamins
b.
A transparent yellowish fluid that contains no red blood cells or platelets
c.
A white fluid that contains probiotics and appears at the site of infections
d.
A greenish fluid that contains abundant platelets and water-soluble vitamins
e.
A viscous, red fluid that contains vitamins and minerals
43. Certain types of fibers and complex proteins that are degraded by GI bacteria are called ____.
a.
prebiotics
b.
probiotics
c.
postbiotics
d.
symbiotics
e.
abiotics
44. Microorganisms in food that are viable when consumed and that are beneficial to health are known as
____.
a.
probiotics
b.
prebiotics
c.
postbiotics
d.
symbiotics
e.
abiotics
45. When consumed on a regular basis, which food promotes healthful changes in the microflora of the GI
tract?
a.
Fish
b.
Yogurt
c.
Poultry
d.
Iron-rich foods
e.
Natural sugars
46. The gastrointestinal microbiome is comprised primarily of ____.
a.
villi
b.
bacteria
c.
mucosa
d.
probiotics
e.
viruses
47. What is the primary role of the normal, thriving intestinal bacterial population?
a.
It helps degrade meat and dairy proteins.
b.
It helps prevent infectious bacteria from attacking the system.
c.
It synthesizes vitamin D, which can be absorbed into the body.
d.
It synthesizes several amino acids, which can be absorbed into the body.
e.
It aids in the absorption of essential nutrients.
48. Which substance is known to be produced by small intestinal bacteria?
a.
Mucus
b.
Chyme
c.
Glucose
d.
Vitamins
e.
Protein
49. What two systems coordinate all digestive/absorptive processes?
a.
Enzyme and thoracic
b.
Portal and lymphatic
c.
Nervous and endocrine
d.
Transport and circulatory
e.
Circulatory and nervous
50. What is the normal pH of the stomach?
a.
0.25-0.75
b.
1.5-1.7
c.
2.0-2.5
d.
7.5-8.0
e.
8.5-9.0
51. Which substance regulates the pH of the stomach?
a.
Gastrin
b.
Insulin
c.
Secretin
d.
Cholecystokinin
e.
Glucagon
52. Which substance functions to control the release of hydrochloric acid to prevent excessive acidity?
a.
Insulin
b.
Gastrin
c.
Secretin
d.
Cholecystokinin
e.
Glucagon
53. Which substance stimulates the pancreas to release bicarbonate-rich juice?
a.
Gastrin
b.
Secretin
c.
Glucagon
d.
Gastric-inhibitory peptide
e.
CCK
54. Which characteristic describes pancreatic digestive enzyme function?
a.
The major hormone controlling the release of pancreatic enzymes is gastrin
b.
The release of pancreatic enzymes is controlled primarily by a pancreatic sphincter
c.
The pancreas can increase the activity of fat-degrading enzymes in response to more fat in
the diet
d.
In general, the amounts of digestive enzymes secreted by the pancreas remain constant
over a wide range of nutrient intakes
e.
Pancreatic enzymes can digest protein and fat but not carbohydrate
55. The presence of fat in the intestines stimulates cells of the intestinal wall to release ____.
a.
lipase
b.
gastrin
c.
secretin
d.
cholecystokinin
e.
glucagon
56. What substance controls the release of bile into the small intestine?
a.
Gastrin
b.
Secretin
c.
Prozymogen
d.
Cholecystokinin
e.
Insulin
57. Which action is associated with the presence of fat in the GI tract?
a.
Inhibition of mucosal enzyme activities
b.
Slowing of the process of digestion and absorption
c.
Inhibition of thiamin, riboflavin, and niacin absorption
d.
Stimulation and hastening of digestion and absorption
e.
Markedly decreased transit time
58. What is intestinal ischemia?
a.
Reduced blood flow to the intestines
b.
Chronic episodes of reverse peristalsis
c.
Construction of intestinal lymph supply
d.
Inflammation of two or more sphincter muscles
e.
Severe and repeated episodes of intestinal blockage
59. Which of the following results from reverse peristalsis?
a.
Gas
b.
Choking
c.
Vomiting
d.
Diarrhea
e.
Constipation
60. A person with chronic diarrhea is at risk for which of the following?
a.
Dehydration
b.
Paradoxical constipation
c.
Peptic ulcers
d.
Heimlich’s disease
e.
GERD
61. Inflammation of the large intestine is known as ____.
a.
colitis
b.
indigestion
c.
hemorrhoiditis
d.
acid dysregulation
e.
diverticulitis
62. Which statement describes a feature of irritable bowel syndrome?
a.
Abdominal discomfort is usually mild.
b.
Effective treatment includes peppermint oil.
c.
Constipation rather than diarrhea is the major adverse effect.
d.
A combination of stress plus certain foods is needed to trigger an attack.
e.
It is an autoimmune disease.