Deck 15: The Digestion and Absorption of Food

Question 1

In the small intestine,

A)Acidic chyme is neutralized
B)Mineral ions are actively absorbed
C)Fatty acids are actively absorbed
D)Both acidic chyme is neutralized and mineral ions are actively absorbed occur
E)Both acidic chyme is neutralized and fatty acids are actively absorbed occur

Answer 1

D

Question 2

The source of enzymes that cleave disaccharides into monosaccharides is

A)The pancreas
B)The liver
C)Gastric secretory cells
D)Cells lining the mucosa of the small intestine
E)Salivary glands

Answer 2

D

Question 3

The absorption of iron

A)Is active
B)Is generally 100 percent of the amount ingested
C)Results in storage as ferritin in intestinal epithelial cells
D)Both is active and is generally 100 percent of the amount ingested are correct
E)Both is active and results in storage as ferritin in intestinal epithelial cells are correct

Answer 3

E

Question 4

Which of the following statements regarding neural regulation of gastrointestinal function is true?

A)Networks of nerve cells in the wall of the GI tract innervate the wall's smooth muscle
B)Smooth muscle of the GI tract is innervated by both sympathetic and motor nerves
C)If the autonomic nerves to the GI tract were cut, digestion and absorption of food could no longer take place
D)Both networks of nerve cells in the wall of the GI tract innervate the wall's smooth muscle and smooth muscle of the GI tract is innervated by both sympathetic and motor nerves are correct
E)Both networks of nerve cells in the wall of the GI tract innervate the wall's smooth muscle and if the autonomic nerves to the GI tract were cut, digestion and absorption of food could no longer take place are correct

Question 5

Which of the following statements is true regarding the emulsification of fats?

A)Fat emulsification requires pancreatic lipase
B)Fat emulsification requires secretion of bile salts and phospholipids by the liver
C)Fat emulsification results in the formation of small fat droplets
D)Both fat emulsification requires pancreatic lipase and fat emulsification requires secretion of bile salts and phospholipids by the liver are correct
E)Both fat emulsification requires secretion of bile salts and phospholipids by the liver and fat emulsification results in the formation of small fat droplets are correct

Question 6

Receptors for digestive reflexes

A)Are located in the gastrointestinal tract wall
B)Include chemoreceptors, osmoreceptors, and mechanoreceptors
C)May relay information to integrative centers in the CNS or the enteric plexuses
D)May be endocrine cells
E)Are all of these choices

Question 7

Which of the following statements about neural control of digestion is not true?

A)Parasympathetic stimulation is excitatory to digestion
B)Sympathetic stimulation is generally inhibitory to digestion
C)Local nerve networks (nerve plexuses) stimulate digestive functions
D)Under normal circumstances, nerve plexuses regulate digestion without input from the autonomic nervous system
E)None of the choices are correct

Question 8

Which of the following enzymes is most active at an acid pH?

A)Amylase
B)Lipase
C)Trypsin
D)Pepsin
E)All of the choices are correct

Question 9

Intrinsic factor

A)Is necessary for digestion of vitamin B12
B)Is secreted by parietal cells in the gastric mucosa
C)Deficiency is associated with anemia
D)Both is necessary for digestion of vitamin B12 and is secreted by parietal cells in the gastric mucosa are correct
E)Both is secreted by parietal cells in the gastric mucosa and deficiency is associated with anemia are correct

Question 10

The most important function of saliva is to

A)Moisten and lubricate food for swallowing
B)Digest starch
C)Enhance the sense of taste
D)Kill bacteria
E)Humidify the sinuses and pharynx

Question 11

Lipase

A)Catalyzes the breakdown of triacylglycerol to glycerol and three fatty acids
B)Emulsifies lipids
C)Is secreted by the endocrine pancreas
D)Both catalyzes the breakdown of triacylglycerol to glycerol and three fatty acids and emulsifies lipids are correct
E)None of the choices are correct

Question 12

Gastrointestinal function depends upon each of the following processes except

A)Digestion
B)Filtration
C)Secretion
D)Motility
E)Absorption

Question 13

The functions of the stomach include

A)The complete digestion of protein
B)Dissolving all the food that enters it
C)Killing bacteria
D)Storing partially digested food
E)Killing bacteria and storing partially digested food

Question 14

Which of the following statements regarding protein digestion and absorption is true?

A)Only the stomach and exocrine pancreas produce enzymes that digest protein
B)The products of protein digestion are carried by blood directly to the liver
C)Pepsin digests protein in the small intestine
D)The enzymes that digest protein are secreted in active form
E)Only free amino acids are absorbed across the intestinal epithelium

Question 15

Which of the following statements regarding hormonal regulation of gastrointestinal function is true?

A)The presence of hydrogen ion in the small intestine stimulates secretion of secretin, which in turn stimulates bicarbonate secretion by the pancreas
B)The presence of fatty acids in the small intestine stimulates secretion of CCK, which in turn stimulates enzyme secretion by the pancreas
C)The presence of amino acids in the small intestine stimulates secretion of gastrin, which in turn stimulates HCl secretion by parietal cells
D)Both the presence of hydrogen ion in the small intestine stimulates secretion of secretin, which in turn stimulates bicarbonate secretion by the pancreas and the presence of fatty acids in the small intestine stimulates secretion of CCK, which in turn stimulates enzyme secretion by the pancreas are true
E)All of the choices are true

Question 16

Which of the following statements regarding digestion and absorption of carbohydrates is true?

A)Carbohydrate digestion begins in the stomach
B)Lactose intolerance results from amylase insufficiency
C)Digestible polysaccharides are broken down to maltose and then to glucose
D)Sucrose is absorbed by active transport across the intestinal epithelium
E)All of the choices are true

Question 17

Which of the following molecules crosses the luminal membrane of intestinal cells by facilitated diffusion?

A)Glucose
B)Lactose
C)Fructose
D)Both glucose and lactose are correct
E)All of the choices are correct

Question 18

The enzyme that breaks down starch to short chains is secreted by

A)The salivary glands
B)Pancreatic exocrine cells
C)Pancreatic duct cells
D)The salivary glands and pancreatic exocrine cells
E)The salivary glands and pancreatic duct cells

Question 19

Fat-soluble vitamins

A)Must be digested to fatty acids and monoglyceride
B)Include vitamins A, B12, and D
C)Circulate in chylomicrons
D)Both must be digested to fatty acids and monoglyceride and include vitamins A, B12, and D are correct
E)Both include vitamins A, B12, and D and circulate in chylomicrons are correct

Question 20

Which of the following statements about the transport of the absorbed products of fat digestion is true?

A)Free fatty acids and monoglycerides are transported to the liver via the hepatic portal vein
B)Products of fat digestion first go to the lymph system, and then to the veins leading to the heart
C)Triacylglycerols are transported to the liver via the hepatic portal vein to be processed
D)Free fatty acids and monoglycerides are transported through the lymph in lipoproteins called chylomicrons
E)None of the choices are correct

Question 21

Regarding endocrine regulation of gastrointestinal processes,

A)The hormone secreted by the stomach is secretin
B)CCK is the primary efferent pathway for a reflex arc controlling the levels of acid in the small intestine
C)Gastrin secretion is controlled in part by parasympathetic nerves
D)Both the hormone secreted by the stomach is secretin and CCK is the primary efferent pathway for a reflex arc controlling the levels of acid in the small intestine are correct
E)Both CCK is the primary efferent pathway for a reflex arc controlling the levels of acid in the small intestine and gastrin secretion is controlled in part by parasympathetic nerves are correct

Question 22

Hydrochloric acid

A)Is secreted by chief cells in the antrum of the stomach
B)Secretion into the stomach lumen is stimulated by histamine
C)Secretion into the stomach lumen is stimulated by gastrin
D)Both is secreted by chief cells in the antrum of the stomach and secretion into the stomach lumen is stimulated by histamine are correct
E)Both secretion into the stomach lumen is stimulated by histamine and secretion into the stomach lumen is stimulated by gastrin are correct

Question 23

Regarding motility in the GI tract,

A)Food is propelled along the tract by waves of smooth-muscle contraction and relaxation called peristalsis
B)During a meal, intestinal motility functions primarily to mix chyme and bring it into contact with the gastric mucosa
C)The rate of gastric emptying is controlled by hormones and by autonomic nerves
D)Both food is propelled along the tract by waves of smooth-muscle contraction and relaxation called peristalsis and during a meal, intestinal motility functions primarily to mix chyme and bring it into contact with the gastric mucosa are correct
E)All of the choices are correct

Question 24

Which of the following breakfasts would remain in the stomach longest?

A)Toast, orange juice, and coffee
B)Fried eggs, bacon, and hash browns
C)A bowl of cereal with skim milk
D)A boiled egg, toast, and juice
E)The type of meal one consumes does not affect the rate of gastric emptying

Question 25

Regurgitation of food from the stomach into the esophagus

A)Is ordinarily inhibited by the upper esophageal sphincter
B)Causes irritation of the esophageal mucosa
C)Causes heartburn
D)Both causes irritation of the esophageal mucosa and causes heartburn are correct
E)All of the choices are correct

Question 26

Which of the following is secreted by the chief cells of the gastric mucosa?

A)Pepsinogen
B)HCl
C)Intrinsic factor
D)Gastrin
E)Pepsin

Question 27

During the contractions of gastric emptying

A)The stomach is induced to contract by increased sympathetic activity
B)The pyloric sphincter opens to allow stomach contents to pass quickly and completely into the duodenum
C)The pyloric sphincter closes to allow only a small amount of liquefied chyme to pass into the duodenum at each contraction of the stomach
D)Both the stomach is induced to contract by increased sympathetic activity and the pyloric sphincter opens to allow stomach contents to pass quickly and completely into the duodenum are correct
E)Both the stomach is induced to contract by increased sympathetic activity and the pyloric sphincter closes to allow only a small amount of liquefied chyme to pass into the duodenum at each contraction of the stomach are correct

Question 28

The type of smooth muscle contraction that is necessary for swallowing is called

A)Peristalsis
B)Mass movement
C)Segmentation
D)Distension
E)Lengthening

Question 29

Regarding the secretion of HCl in the stomach,

A)Hydrogen ion is actively transported into the gastric lumen by ATPase pumps in the mucosal membrane
B)Hydrogen ion is actively transported into the lumen by secondary active transporters coupled to K ion
C)The pH of the blood leaving the area of the parietal cells is lower than normal
D)Both hydrogen ion is actively transported into the gastric lumen by ATPase pumps in the mucosal membrane and the pH of the blood leaving the area of the parietal cells is lower than normal are correct
E)Both hydrogen ion is actively transported into the lumen by secondary active transporters coupled to K ion and the pH of the blood leaving the area of the parietal cells is lower than normal are correct

Question 30

Regarding the three phases of gastrointestinal control:

A)They refer to the places in the GI tract where digestion or absorption is occurring
B)They refer to the locations of receptors for stimuli that trigger hormonal or neural control mechanisms for GI processes
C)The presence of acid in the small intestine is one stimulus for the intestinal phase of GI control
D)Both they refer to the places in the GI tract where digestion or absorption is occurring and the presence of acid in the small intestine is one stimulus for the intestinal phase of GI control are correct
E)Both they refer to the locations of receptors for stimuli that trigger hormonal or neural control mechanisms for GI processes and the presence of acid in the small intestine is one stimulus for the intestinal phase of GI control are correct

Question 31

Which of the following is not a part of the swallowing reflex?

A)Respiration is inhibited
B)The glottis closes
C)The upper esophageal sphincter relaxes
D)The lower esophageal sphincter relaxes
E)The pyloric sphincter relaxes

Question 32

Which of the following statements about gastrin is true?

A)It is a hormone that is secreted by cells in the epithelium of the duodenum
B)It is an enzyme that is secreted into the lumen of the stomach
C)It is a hormone that is secreted in response to sympathetic stimulation
D)It is an enzyme that breaks down proteins
E)It is a hormone that is secreted in response to the presence of peptides in the stomach

Question 33

Which of the following statements concerning secretin is correct?

A)The most potent stimulus for secretin secretion is the presence of fat in the duodenum
B)Secretin is the most potent stimulus for pancreatic enzyme secretion
C)Secretin is the most potent stimulus for pancreatic bicarbonate secretion
D)Secretin stimulates secretion by the parietal and chief cells
E)All of the choices are correct

Question 34

During the cephalic phase of gastric stimulation,all of the following occur except,

A)Seeing, smelling, and/or tasting food reflexly increase(s) gastric acid secretion
B)Parasympathetic stimulation of secretory cells in the gastric mucosa occurs
C)Gastrin is secreted into the gastric lumen
D)HCl is secreted into the gastric lumen
E)Pepsinogen is secreted into the gastric lumen

Question 35

Which of the following is the most potent inhibitor (directly or indirectly)of gastric motility and emptying?

A)Fat in the duodenum
B)Acid in the stomach
C)Carbohydrate in the stomach
D)Gastrin
E)Distension of the stomach

Question 36

Which of the following statements regarding lipid digestion and absorption is true?

A)The presence of fatty acids in the duodenum stimulates the secretion of CCK, which in turn stimulates secretion of pancreatic enzymes
B)The presence of fatty acids in the duodenum stimulates the secretion of CCK, which in turn stimulates contraction of the gallbladder
C)The presence of fatty acids in the duodenum stimulates the secretion of CCK, which in turn stimulates bile synthesis in the gallbladder
D)Both the presence of fatty acids in the duodenum stimulates the secretion of CCK, which in turn stimulates secretion of pancreatic enzymes and the presence of fatty acids in the duodenum stimulates the secretion of CCK, which in turn stimulates contraction of the gallbladder are true
E)Both the presence of fatty acids in the duodenum stimulates the secretion of CCK, which in turn stimulates secretion of pancreatic enzymes and the presence of fatty acids in the duodenum stimulates the secretion of CCK, which in turn stimulates bile synthesis in the gallbladder are true

Question 37

Cholecystokinin

A)Relaxes the sphincter of Oddi
B)Stimulates pancreatic enzyme secretion
C)Stimulates gallbladder contraction
D)Both stimulates pancreatic enzyme secretion and stimulates gallbladder contraction are correct
E)All of the choices are correct

Question 38

Which of the following occurs during the cephalic phase of gastrointestinal control?

A)Secretion of saliva
B)Secretion of gastric acid
C)Secretion of secretin
D)Both secretion of saliva and secretion of gastric acid occur
E)All of these things occur

Question 39

Hydrochloric acid

A)Secretion in the stomach is accompanied by bicarbonate secretion into the blood
B)In the stomach activates trypsinogen
C)Secretion in the stomach is stimulated by the smell of food
D)Both secretion in the stomach is accompanied by bicarbonate secretion into the blood and in the stomach activates trypsinogen are correct
E)Both secretion in the stomach is accompanied by bicarbonate secretion into the blood and secretion in the stomach is stimulated by the smell of food are correct

Question 40

The parietal cells of the gastric mucosa secrete

A)HCl
B)Pepsinogen
C)Intrinsic factor
D)HCl and pepsinogen
E)HCl and intrinsic factor

Question 41

Regarding the motility of the small intestine,

A)It varies depending upon whether a meal is being digested and absorbed
B)During a meal, intestinal motility functions primarily to mix chyme and bring it into contact with intestinal mucosa
C)Segmentation is the primary means of propelling unabsorbed matter toward the large intestine
D)Both it varies depending upon whether a meal is being digested and absorbed and during a meal, intestinal motility functions primarily to mix chyme and bring it into contact with intestinal mucosa are correct
E)All of the choices are correct

Question 42

The primary kind of motility in the small intestine during digestion of a meal is

A)Peristalsis
B)Segmentation
C)Relaxation of the pyloric sphincter
D)Migrating motility complex
E)Mass movement

Question 43

Which of the following is not true about gallstones? Gallstones

A)Are crystallized bile salts
B)May cause pain
C)May cause impaired fat digestion
D)May cause general nutritional deficiencies
E)May cause jaundice

Question 44

A person who lacks the exocrine portion of the pancreas would be unable to

A)Digest fats
B)Digest protein
C)Digest carbohydrate
D)Emulsify fats
E)All of the choices are correct

Question 45

Which of the following statements about pancreatic enzymes is not correct?

A)Trypsinogen is secreted in an inactive form
B)Pancreatic amylase digests carbohydrates
C)Pancreatic lipase digests fats
D)Except for trypsinogen, other proteolytic enzymes are secreted in active form
E)Trypsinogen is activated by enterokinase

Question 46

A person without a gallbladder

A)Cannot secrete bile
B)Cannot store bile
C)Will have difficulty digesting a large, fat-rich meal
D)Both cannot store bile and will have difficulty digesting a large, fat-rich meal are correct
E)All of the choices are correct

Question 47

The primary kind of motility in the stomach during digestion of a meal is

A)Peristalsis
B)Segmentation
C)Relaxation of the pyloric sphincter
D)Mass movement
E)Regurgitation

Question 48

Lactase enzyme

A)Is involved directly in the digestion of proteins
B)Is necessary for the breakdown of milk fats
C)Is embedded in the luminal plasma membranes of intestinal epithelial cells
D)Promotes the formation of and storage of bile by the gallbladder
E)Is overproduced and released by secretory cells in the small intestine in the condition known as lactose intolerance

Question 49

Bile pigments

A)Are important for fat digestion
B)Are formed from catabolism of the globin part of hemoglobin
C)Impart color to the bile, feces, and urine
D)Both are important for fat digestion and are formed from catabolism of the globin part of hemoglobin are correct
E)Both are formed from catabolism of the globin part of hemoglobin and impart color to the bile, feces, and urine are correct

Question 50

Which of the following would be most likely to cause metabolic acidosis?

A)Severe vomiting
B)Severe diarrhea
C)Hyperventilation
D)Hypoventilation
E)None of the choices are correct

Question 51

Bile is synthesized and secreted by the

A)Gallbladder
B)Gastric mucosa
C)Pancreas
D)Duodenum
E)Liver

Question 52

Which of the following statements regarding protein digestion and absorption is true?

A)Cells in the stomach secrete pepsin, which breaks down proteins into smaller peptides
B)Pepsin and trypsin are proteolytic enzymes that are most active in an acid pH
C)More acid is secreted during the digestion of a high-protein meal than during the digestion of a meal containing little protein
D)The presence of peptides in the stomach inhibits secretion of gastrin
E)None of the choices are true

Question 53

Constipation

A)Is associated with symptoms caused by accumulation of toxins in the stool
B)Is caused by failure to defecate at least once a day
C)May be relieved by ingestion of foods with a high proportion of indigestible carbohydrates
D)Both is associated with symptoms caused by accumulation of toxins in the stool and is caused by failure to defecate at least once a day are correct
E)Both is caused by failure to defecate at least once a day and may be relieved by ingestion of foods with a high proportion of indigestible carbohydrates are correct

Question 54

Which of the following is not secreted by the exocrine pancreas?

A)Bicarbonate ions
B)Amylase
C)Bile salts
D)Trypsinogen
E)Lipase

Question 55

Which of the following would be most likely to cause metabolic alkalosis?

A)Severe vomiting
B)Severe diarrhea
C)Hyperventilation
D)Strenuous exercise
E)Hypoventilation

Question 56

Lactose intolerance

A)Is an inability to digest milk sugar
B)Is most common in very young children
C)Can cause painful bloating and diarrhea
D)Both is an inability to digest milk sugar and is most common in very young children are correct
E)Both is an inability to digest milk sugar and can cause painful bloating and diarrhea are correct

Question 57

Ulcers are

A)Most common in the gastric mucosa
B)Always caused by hypersecretion of gastric acid
C)Treated by methods that inhibit acid secretion
D)Both most common in the gastric mucosa and always caused by hypersecretion of gastric acid are correct
E)Both always caused by hypersecretion of gastric acid and treated by methods that inhibit acid secretion are correct

Question 58

With regard to gastric motility,

A)The basic electrical rhythm of the gastric smooth muscle (three depolarizations per minute) is the same regardless of whether or not food is present
B)Gastric smooth muscle contracts three times a minute regardless of whether or not food is present
C)The force of contraction is increased by gastrin and inhibited by enterogastrones
D)Both the basic electrical rhythm of the gastric smooth muscle (three depolarizations per minute) is the same regardless of whether or not food is present and gastric smooth muscle contracts three times a minute regardless of whether or not food is present are correct
E)Both the basic electrical rhythm of the gastric smooth muscle (three depolarizations per minute) is the same regardless of whether or not food is present and the force of contraction is increased by gastrin and inhibited by enterogastrones are correct

Question 59

Bicarbonate is produced by

A)Parietal cells of the stomach
B)Pancreatic duct cells
C)Kidney tubule epithelial cells
D)Pancreatic duct cells and kidney tubule epithelial cells
E)All of the choices are correct

Question 60

Peristaltic contractions occur in

A)The small intestine
B)The large intestine
C)The stomach
D)The esophagus
E)All of the choices are correct

Question 61

The products of lipid digestion diffuse into the intestinal epithelium as micelles.

Question 62

The presence of food in the mouth stimulates salivary gland secretion.

Question 63

The pH of the contents of the stomach lumen is considerably higher than that of interstitial fluid.

Question 64

Following a "meal" that consists solely of carbohydrate (for example,sugar cubes),no amino acids will be absorbed by the small intestine.

Question 65

Three enzymes secreted by the pancreas and important for protein digestion are trypsin,chymotrypsin,and pepsin.

Question 66

Contraction of the circular smooth muscle in the gastrointestinal tract wall decreases the diameter of the lumen,while contraction of the longitudinal smooth muscle shortens the tract.

Question 67

The most abundant solute in chyme is sodium.

Question 68

Glucose absorption occurs by active transport.

Question 69

Inflammatory bowel disease is characterized by all of the following,except:

A)Bleeding, edema, and ulceration anywhere along the gastrointestinal tract
B)Diarrhea and excessively loose and watery stools
C)Perforations in the mucosa and intestinal wall leading to infection by bacteria which are normally present and benign
D)Can cause inflammation and thickening of the bowel wall to the point of preventing the usual passage of feces
E)Pain in the lower right abdomen frequently mistaken for appendicitis

Question 70

The exact causes of inflammatory bowel diseases continue to be explored,but it is relatively clear that

A)The condition is quite common among people of all ages and subgroups within the population
B)Inflammatory bowel disease is likely to be passed on through genetic inheritance
C)Individuals suffering from its effects are largely experiencing the consequences of the complete failure of normal immune mechanisms in the gastrointestinal tract
D)It can be easily diagnosed since its symptoms are always very specific and the affected areas are always limited to a very focused area within the small intestine
E)By careful examination of one's diet is relatively easy to recommend the elimination of certain foods and the addition of others to provide immediate relief without the need to administer specific drug therapy

Question 71

The breakdown products of dietary fats are resynthesized into fat by intestinal cells and pass from these cells into lacteals.

Question 72

The function of micelles is to store the products of lipid digestion in water-soluble form.

Question 73

Short chains of amino acids and some intact proteins are absorbed from the small intestine.

Question 74

The lumen of the gastrointestinal tract is continuous with the external environment.

Question 75

Neural regulation of digestive processes is accomplished exclusively by the enteric nervous system of the gastrointestinal tract.

Question 76

The presence of acid and peptides in the stomach stimulates the gastric phase of gastrointestinal control.

Question 77

Polysaccharides must be broken down to disaccharides in order to be absorbed.

Question 78

The liver and pancreas are components of the gastrointestinal tract.

Question 79

In patients lacking exocrine pancreas secretion,fat digestion is normal provided bile is still produced.

Question 80

The volume of fluids secreted by the gastrointestinal tract in a day is far greater than the volume of food and drink ingested.