Chapter 01: Intake: Gastrointestinal Digestion, Absorption, and Excretion of Nutrients
g g g g g g g g g
Raymond: Krause and Mahan’s Food and the Nutrition Care Process, 16th Edition
g g g g g g g g g g g g
MULTIPLE CHOICE g
1. Pepsinogen is converted to pepsin when it comes in contact with g g g g g g g g g g
a. enterokinase.
b. trypsinogen.
c. hydrochloric acid. g
d. peptidases.
ANS: C g
Pepsinogen is secreted in the stomach and converted to its active form by the acid environment
g g g g g g g g g g g g g g g
of the stomach. Enterokinase is secreted by the brush border of the small intestine in response to
g g g g g g g g g g g g g g g g g
the presence of chyme. Trypsinogen is secreted by the pancreas and activated by enterokinase.
g g g g g g g g g g g g g g
Various peptidases are secreted by the either brush border or the pancreas.
g g g g g g g g g g g g
2. Which of the following is formed by bacterial synthesis in the colon?
g g g g g g g g g g g
a. Vitamin K g
b. Vitamin D g
c. Vitamin B6 g
d. Niacin
ANS: A g
Colonic bacteria produce vitamin K, vitamin B12, thiamin, and riboflavin. Vitamin D may be
g g g g g g g g g g g g g
metabolized by exposure of precursor vitamin D in the skin to ultraviolet light. The human
g g g g g g g g g g g g g g g
body can synthesize niacin from the amino acid tryptophan. Vitamin B6 must be obtained from
g g g g g g g g g g g g g g g
dietary sources such as meats, whole grains, vegetables, and nuts.
g g g g g g g g g g
3. After surgical removal of a large portion of the small intestine, what functional complication is
g g g g g g g g g g g g g g
gmost likely to develop?
g g g
a. Changes in dietary habits g g g
b. Impaired digestion g
c. Loss of absorptive tissue g g g
d. Elimination of dietary residue g g g
ANS: C g
The small intestine is the primary site of nutrient absorption because of its large absorption
g g g g g g g g g g g g g g
surface area. Secretions from the liver, gallbladder, and pancreas can still contribute to
g g g g g g g g g g g g g
digestion of intestinal contents. However, decreased absorption of nutrients and food
g g g g g g g g g g g
components may result in more intestinal remains and residue. A patient may change dietary
g g g g g g g g g g g g g g
habits as a result of gastrointestinal discomfort experienced after intestinal resection, but this is
g g g g g g g g g g g g g g
not a functional complication.
g g g g
4. The sight or smell of food produces vagal stimulation of the parietal cells of the gastric
g g g g g g g g g g g g g g g
gmucosa, resulting in the increased production of what?
g g g g g g g
a. Motilin
b. Gastrin
c. Cholecystokinin
d. Secretin
, ANS: B g
Parasympathetic innervation that causes secretion of gastrin and release of hydrochloric acid g g g g g g g g g g g
helps prepare the stomach for the potential of receiving food. After food chyme is passed into the
g g g g g g g g g g g g g g g g g
small intestine from the stomach, secretin and cholecystokinin are secreted to stimulate
g g g g g g g g g g g g
pancreatic secretion of water and bicarbonate. They also signal gallbladder contractions and
g g g g g g g g g g g g
colonic motility, all resulting in reductions in stomach emptying and duodenal motility.
g g g g g g g g g g g g
Motilin is secreted from the duodenal mucosa during fasting to stimulate gastric emptying and
g g g g g g g g g g g g g
intestinal motility.
g g
5. If a patient experiences malabsorption of fat resulting from an impaired ability to produce
g g g g g g g g g g g g g
gadequate bile salts for micelle formation, how may fat absorption be improved?
g g g g g g g g g g g
a. By increasing short-chain fatty acids in the diet
g g g g g g g
b. By increasing medium-chain fatty acids in the diet
g g g g g g g
c. By increasing long-chain fatty acids in the diet
g g g g g g g
d. By restricting dietary intake of cholesterol
g g g g g
ANS: B g
Medium-chain fatty acids of 8 to 12 carbons can be absorbed directly by mucosal cells without g g g g g g g g g g g g g g g
the presence of bile. The long-chain fatty acids require micelle formation for absorption.
g g g g g g g g g g g g g
Short-chain fatty acids result from bacterial fermentation of malabsorbed carbohydrates and
g g g g g g g g g g g
fibers. As bile is produced from cholesterol, dietary restriction of cholesterol is negligible in
g g g g g g g g g g g g g g
regard to improvements in fat absorption.
g g g g g g
6. What is the function of secretin?
g g g g g
a. Stimulation of gastric secretions and increased motility g g g g g g
b. Stimulation of gallbladder contraction and the release of bile g g g g g g g g
c. Stimulation of the pancreas to secrete water and bicarbonate g g g g g g g g
d. Stimulation of the parietal cells to secrete gastrin g g g g g g g
ANS: C g
Secretin is the hormone that works in opposition to gastrin. Whereas gastrin stimulates stomach
g g g g g g g g g g g g g
digestion activities, secretin decreases gastric output and promotes pancreatic secretions to
g g g g g g g g g g g
neutralize the acidity of chyme. Cholecystokinin is also secreted when chyme enters the
g g g g g g g g g g g g g
duodenum, and it is responsible for stimulating the gallbladder.
g g g g g g g g g
7. Which of the following is a list of enzymes released from the pancreas?
g g g g g g g g g g g g
a. Insulin, trypsin, and secretin g g g
b. Lactase, isomaltase, and dextrinase g g g
c. Protease, pepsin, and gastrin g g g
d. Trypsin, chymotrypsin, and carboxypeptidase g g g
ANS: D g
Trypsin, chymotrypsin, and carboxypeptidase are three protein digestive enzymes secreted by
g g g g g g g g g g
the pancreas. Insulin is an endogenous hormone secreted by the pancreas. Secretin is a hormone
g g g g g g g g g g g g g g g
secreted by the small intestine. Lactase and isomaltase (also known as dextrinase) are brush-
g g g g g g g g g g g g g g
border enzymes. Pepsin, which is a protease, and gastrin are hormones secreted by the stomach.
g g g g g g g g g g g g g g
8. In what form is dietary fat absorbed from the lumen of the intestine?
g g g g g g g g g g g g
, a. Chylomicron
b. Micelle
c. Triglyceride
d. Lipoprotein
ANS: B g
Fats must be emulsified into micelles so that they may cross the unstirred water layer that
g g g g g g g g g g g g g g g
borders the brush-border membranes. These micelles leave monoglycerides and fatty acids at
g g g g g g g g g g g g
the brush border, where they are reabsorbed and reassembled as triglycerides. The triglycerides
g g g g g g g g g g g g g
are packaged with cholesterol, fat-soluble vitamins, and phospholipids into chylomicrons,
g g g g g g g g g g
which pass into the lymphatic circulation. When these reach the liver, the chylomicron
g g g g g g g g g g g g g
components are repackaged into low-density lipoproteins.
g g g g g g
9. Which of the following is true of probiotics?
g g g g g g g
a. Probiotics are live microorganisms found in food. g g g g g g
b. Probiotics are nondigestible carbohydrates. g g g
c. Probiotics act primarily on bacteria in the proximal small intestine.
g g g g g g g g g
d. Probiotics cannot be given as supplements because they readily die.
g g g g g g g g g
ANS: A g
Probiotics are live microorganisms, which when administered in adequate amounts confer a
g g g g g g g g g g g
health benefit on the host. They are found in fermented foods like yogurt and sauerkraut or as a
g g g g g g g g g g g g g g g g g g
nutritional supplement. Bacterial action is most intense in the distal small intestine and large
g g g g g g g g g g g g g g
intestine.
g
10. By which transport mechanism are most vitamins absorbed from the small intestine into the
g g g g g g g g g g g g g
gblood?
a. Passive diffusion g
b. Active diffusion g
c. Facilitative diffusion g
d. Passive osmosis g
ANS: A g
Passive diffusion is limited by the number of channels available for nutrients to randomly pass
g g g g g g g g g g g g g g
through. Facilitated diffusion requires the presence of carrier proteins, which may be limited by
g g g g g g g g g g g g g g
the health and nutritional status of the person. Active transport requires energy, which also may
g g g g g g g g g g g g g g g
be limited by the person’s health and nutritional status. Osmosis occurs in regard to
g g g g g g g g g g g g g g
concentration gradient and only involves the movement of water, not vitamins.
g g g g g g g g g g g
11. What are primarily absorbed by the large intestine?
g g g g g g g
a. Water and fats g g
b. Carbohydrates
c. Proteins
d. Water and electrolytes g g
ANS: D g
Water and electrolytes are usually the only absorbable remnants of dietary intake that reach the
g g g g g g g g g g g g g g
large intestine. Fats, carbohydrates, and proteins from the diet are absorbed throughout the small
g g g g g g g g g g g g g g
intestine.
g
12. What happens to cellulose and lignin as they go through the GI tract?
g g g g g g g g g g g g
, a. They are converted into glucose before absorption.
g g g g g g
b. They are converted into glucose and absorbed by active transport.
g g g g g g g g g
c. They are excreted in the feces unchanged.
g g g g g g
d. They are excreted in the feces as glucose.
g g g g g g g
ANS: C g
In humans, the secreted amylases cannot split the 1-2 and 1-4 linkages between the
g g g g g g g g g g g g g
saccharides within the cellulose molecule. As a result, no individual glucose molecules are
g g g g g g g g g g g g g
broken off.
g g
13. Which is the process by which minerals are absorbed when they are bound to an acid, organic
g g g g g g g g g g g g g g g g
acid, or amino acid?
g g g g
a. Cotransportation
b. Carrier protein g
c. Competitive inhibition g
d. Chelation
ANS: D g
Chelation refers to the binding of a cation mineral to a ligand, not a whole protein.
g g g g g g g g g g g g g g g
Cotransporters carry two different minerals at a time, such as the case with sodium and
g g g g g g g g g g g g g g g
phosphorus. An overlap of mineral transport mechanisms may lead to competitive absorption
g g g g g g g g g g g g
between minerals in the presence of other minerals, such as the case with iron or zinc
g g g g g g g g g g g g g g g g
supplementation, leading to a decrease in copper absorption.
g g g g g g g g
14. How often do the cells lining the intestinal tract recycle?
g g g g g g g g g
a. Every 2 to 3 days g g g g
b. Every 3 to 5 days g g g g
c. Every 5 to 7 days g g g g
d. Every 10 to 14 days g g g g
ANS: B g
Intestinal mucosal cells have a life span of 3 to 5 days before they are sloughed off and recycled.
g g g g g g g g g g g g g g g g g g
They are fully functional only for the last 2 to 3 days as they migrate to the distal third of the villi.
g g g g g g g g g g g g g g g g g g g g g g
15. What effect may be achieved by eating a diet high in prebiotic carbohydrates?
g g g g g g g g g g g g
a. Decreased SCFA production in the bowel g g g g g
b. Increased growth of Lactobacillus spp. g g g g
c. Decreased absorption of bile salts g g g g
d. Increased absorption of cation minerals g g g g
ANS: B g
The use of prebiotic carbohydrates favors the growth of friendly bacteria such as lactobacilli
g g g g g g g g g g g g g
and bifidobacteria. These bacteria ferment the prebiotic carbohydrates, promoting increased
g g g g g g g g g g
short-chain fatty acid production. These types of carbohydrates have not been demonstrated to
g g g g g g g g g g g g g
have a bile-sequestering effect. Impairments in absorption of cation minerals tend to be in
g g g g g g g g g g g g g g
relation to phytates and oxalates that are present in plant foods.
g g g g g g g g g g g
16. How long does it take for small intestine contents to reach the ileocecal valve?
g g g g g g g g g g g g g
a. 18 to 72 hours g g g
b. 3 to 8 hours
g g g
c. 1 to 2 hours g g g
g g g g g g g g g
Raymond: Krause and Mahan’s Food and the Nutrition Care Process, 16th Edition
g g g g g g g g g g g g
MULTIPLE CHOICE g
1. Pepsinogen is converted to pepsin when it comes in contact with g g g g g g g g g g
a. enterokinase.
b. trypsinogen.
c. hydrochloric acid. g
d. peptidases.
ANS: C g
Pepsinogen is secreted in the stomach and converted to its active form by the acid environment
g g g g g g g g g g g g g g g
of the stomach. Enterokinase is secreted by the brush border of the small intestine in response to
g g g g g g g g g g g g g g g g g
the presence of chyme. Trypsinogen is secreted by the pancreas and activated by enterokinase.
g g g g g g g g g g g g g g
Various peptidases are secreted by the either brush border or the pancreas.
g g g g g g g g g g g g
2. Which of the following is formed by bacterial synthesis in the colon?
g g g g g g g g g g g
a. Vitamin K g
b. Vitamin D g
c. Vitamin B6 g
d. Niacin
ANS: A g
Colonic bacteria produce vitamin K, vitamin B12, thiamin, and riboflavin. Vitamin D may be
g g g g g g g g g g g g g
metabolized by exposure of precursor vitamin D in the skin to ultraviolet light. The human
g g g g g g g g g g g g g g g
body can synthesize niacin from the amino acid tryptophan. Vitamin B6 must be obtained from
g g g g g g g g g g g g g g g
dietary sources such as meats, whole grains, vegetables, and nuts.
g g g g g g g g g g
3. After surgical removal of a large portion of the small intestine, what functional complication is
g g g g g g g g g g g g g g
gmost likely to develop?
g g g
a. Changes in dietary habits g g g
b. Impaired digestion g
c. Loss of absorptive tissue g g g
d. Elimination of dietary residue g g g
ANS: C g
The small intestine is the primary site of nutrient absorption because of its large absorption
g g g g g g g g g g g g g g
surface area. Secretions from the liver, gallbladder, and pancreas can still contribute to
g g g g g g g g g g g g g
digestion of intestinal contents. However, decreased absorption of nutrients and food
g g g g g g g g g g g
components may result in more intestinal remains and residue. A patient may change dietary
g g g g g g g g g g g g g g
habits as a result of gastrointestinal discomfort experienced after intestinal resection, but this is
g g g g g g g g g g g g g g
not a functional complication.
g g g g
4. The sight or smell of food produces vagal stimulation of the parietal cells of the gastric
g g g g g g g g g g g g g g g
gmucosa, resulting in the increased production of what?
g g g g g g g
a. Motilin
b. Gastrin
c. Cholecystokinin
d. Secretin
, ANS: B g
Parasympathetic innervation that causes secretion of gastrin and release of hydrochloric acid g g g g g g g g g g g
helps prepare the stomach for the potential of receiving food. After food chyme is passed into the
g g g g g g g g g g g g g g g g g
small intestine from the stomach, secretin and cholecystokinin are secreted to stimulate
g g g g g g g g g g g g
pancreatic secretion of water and bicarbonate. They also signal gallbladder contractions and
g g g g g g g g g g g g
colonic motility, all resulting in reductions in stomach emptying and duodenal motility.
g g g g g g g g g g g g
Motilin is secreted from the duodenal mucosa during fasting to stimulate gastric emptying and
g g g g g g g g g g g g g
intestinal motility.
g g
5. If a patient experiences malabsorption of fat resulting from an impaired ability to produce
g g g g g g g g g g g g g
gadequate bile salts for micelle formation, how may fat absorption be improved?
g g g g g g g g g g g
a. By increasing short-chain fatty acids in the diet
g g g g g g g
b. By increasing medium-chain fatty acids in the diet
g g g g g g g
c. By increasing long-chain fatty acids in the diet
g g g g g g g
d. By restricting dietary intake of cholesterol
g g g g g
ANS: B g
Medium-chain fatty acids of 8 to 12 carbons can be absorbed directly by mucosal cells without g g g g g g g g g g g g g g g
the presence of bile. The long-chain fatty acids require micelle formation for absorption.
g g g g g g g g g g g g g
Short-chain fatty acids result from bacterial fermentation of malabsorbed carbohydrates and
g g g g g g g g g g g
fibers. As bile is produced from cholesterol, dietary restriction of cholesterol is negligible in
g g g g g g g g g g g g g g
regard to improvements in fat absorption.
g g g g g g
6. What is the function of secretin?
g g g g g
a. Stimulation of gastric secretions and increased motility g g g g g g
b. Stimulation of gallbladder contraction and the release of bile g g g g g g g g
c. Stimulation of the pancreas to secrete water and bicarbonate g g g g g g g g
d. Stimulation of the parietal cells to secrete gastrin g g g g g g g
ANS: C g
Secretin is the hormone that works in opposition to gastrin. Whereas gastrin stimulates stomach
g g g g g g g g g g g g g
digestion activities, secretin decreases gastric output and promotes pancreatic secretions to
g g g g g g g g g g g
neutralize the acidity of chyme. Cholecystokinin is also secreted when chyme enters the
g g g g g g g g g g g g g
duodenum, and it is responsible for stimulating the gallbladder.
g g g g g g g g g
7. Which of the following is a list of enzymes released from the pancreas?
g g g g g g g g g g g g
a. Insulin, trypsin, and secretin g g g
b. Lactase, isomaltase, and dextrinase g g g
c. Protease, pepsin, and gastrin g g g
d. Trypsin, chymotrypsin, and carboxypeptidase g g g
ANS: D g
Trypsin, chymotrypsin, and carboxypeptidase are three protein digestive enzymes secreted by
g g g g g g g g g g
the pancreas. Insulin is an endogenous hormone secreted by the pancreas. Secretin is a hormone
g g g g g g g g g g g g g g g
secreted by the small intestine. Lactase and isomaltase (also known as dextrinase) are brush-
g g g g g g g g g g g g g g
border enzymes. Pepsin, which is a protease, and gastrin are hormones secreted by the stomach.
g g g g g g g g g g g g g g
8. In what form is dietary fat absorbed from the lumen of the intestine?
g g g g g g g g g g g g
, a. Chylomicron
b. Micelle
c. Triglyceride
d. Lipoprotein
ANS: B g
Fats must be emulsified into micelles so that they may cross the unstirred water layer that
g g g g g g g g g g g g g g g
borders the brush-border membranes. These micelles leave monoglycerides and fatty acids at
g g g g g g g g g g g g
the brush border, where they are reabsorbed and reassembled as triglycerides. The triglycerides
g g g g g g g g g g g g g
are packaged with cholesterol, fat-soluble vitamins, and phospholipids into chylomicrons,
g g g g g g g g g g
which pass into the lymphatic circulation. When these reach the liver, the chylomicron
g g g g g g g g g g g g g
components are repackaged into low-density lipoproteins.
g g g g g g
9. Which of the following is true of probiotics?
g g g g g g g
a. Probiotics are live microorganisms found in food. g g g g g g
b. Probiotics are nondigestible carbohydrates. g g g
c. Probiotics act primarily on bacteria in the proximal small intestine.
g g g g g g g g g
d. Probiotics cannot be given as supplements because they readily die.
g g g g g g g g g
ANS: A g
Probiotics are live microorganisms, which when administered in adequate amounts confer a
g g g g g g g g g g g
health benefit on the host. They are found in fermented foods like yogurt and sauerkraut or as a
g g g g g g g g g g g g g g g g g g
nutritional supplement. Bacterial action is most intense in the distal small intestine and large
g g g g g g g g g g g g g g
intestine.
g
10. By which transport mechanism are most vitamins absorbed from the small intestine into the
g g g g g g g g g g g g g
gblood?
a. Passive diffusion g
b. Active diffusion g
c. Facilitative diffusion g
d. Passive osmosis g
ANS: A g
Passive diffusion is limited by the number of channels available for nutrients to randomly pass
g g g g g g g g g g g g g g
through. Facilitated diffusion requires the presence of carrier proteins, which may be limited by
g g g g g g g g g g g g g g
the health and nutritional status of the person. Active transport requires energy, which also may
g g g g g g g g g g g g g g g
be limited by the person’s health and nutritional status. Osmosis occurs in regard to
g g g g g g g g g g g g g g
concentration gradient and only involves the movement of water, not vitamins.
g g g g g g g g g g g
11. What are primarily absorbed by the large intestine?
g g g g g g g
a. Water and fats g g
b. Carbohydrates
c. Proteins
d. Water and electrolytes g g
ANS: D g
Water and electrolytes are usually the only absorbable remnants of dietary intake that reach the
g g g g g g g g g g g g g g
large intestine. Fats, carbohydrates, and proteins from the diet are absorbed throughout the small
g g g g g g g g g g g g g g
intestine.
g
12. What happens to cellulose and lignin as they go through the GI tract?
g g g g g g g g g g g g
, a. They are converted into glucose before absorption.
g g g g g g
b. They are converted into glucose and absorbed by active transport.
g g g g g g g g g
c. They are excreted in the feces unchanged.
g g g g g g
d. They are excreted in the feces as glucose.
g g g g g g g
ANS: C g
In humans, the secreted amylases cannot split the 1-2 and 1-4 linkages between the
g g g g g g g g g g g g g
saccharides within the cellulose molecule. As a result, no individual glucose molecules are
g g g g g g g g g g g g g
broken off.
g g
13. Which is the process by which minerals are absorbed when they are bound to an acid, organic
g g g g g g g g g g g g g g g g
acid, or amino acid?
g g g g
a. Cotransportation
b. Carrier protein g
c. Competitive inhibition g
d. Chelation
ANS: D g
Chelation refers to the binding of a cation mineral to a ligand, not a whole protein.
g g g g g g g g g g g g g g g
Cotransporters carry two different minerals at a time, such as the case with sodium and
g g g g g g g g g g g g g g g
phosphorus. An overlap of mineral transport mechanisms may lead to competitive absorption
g g g g g g g g g g g g
between minerals in the presence of other minerals, such as the case with iron or zinc
g g g g g g g g g g g g g g g g
supplementation, leading to a decrease in copper absorption.
g g g g g g g g
14. How often do the cells lining the intestinal tract recycle?
g g g g g g g g g
a. Every 2 to 3 days g g g g
b. Every 3 to 5 days g g g g
c. Every 5 to 7 days g g g g
d. Every 10 to 14 days g g g g
ANS: B g
Intestinal mucosal cells have a life span of 3 to 5 days before they are sloughed off and recycled.
g g g g g g g g g g g g g g g g g g
They are fully functional only for the last 2 to 3 days as they migrate to the distal third of the villi.
g g g g g g g g g g g g g g g g g g g g g g
15. What effect may be achieved by eating a diet high in prebiotic carbohydrates?
g g g g g g g g g g g g
a. Decreased SCFA production in the bowel g g g g g
b. Increased growth of Lactobacillus spp. g g g g
c. Decreased absorption of bile salts g g g g
d. Increased absorption of cation minerals g g g g
ANS: B g
The use of prebiotic carbohydrates favors the growth of friendly bacteria such as lactobacilli
g g g g g g g g g g g g g
and bifidobacteria. These bacteria ferment the prebiotic carbohydrates, promoting increased
g g g g g g g g g g
short-chain fatty acid production. These types of carbohydrates have not been demonstrated to
g g g g g g g g g g g g g
have a bile-sequestering effect. Impairments in absorption of cation minerals tend to be in
g g g g g g g g g g g g g g
relation to phytates and oxalates that are present in plant foods.
g g g g g g g g g g g
16. How long does it take for small intestine contents to reach the ileocecal valve?
g g g g g g g g g g g g g
a. 18 to 72 hours g g g
b. 3 to 8 hours
g g g
c. 1 to 2 hours g g g
