Deck 40: Digestion and Absorption

Question 1

The final product of carbohydrate digestion is a:

A)disaccharide.
B)monosaccharide.
C)polysaccharide.
D)fatty acid.

Answer 1

B

Question 2

The purpose of peristalsis is to:

A)break apart chunks of food and mix it in digestive juices.
B)propel food forward along the GI tract.
C)absorb food.
D)enable swallowing.

Answer 2

B

Question 3

Which of the following is a true statement?

A)The oral stage of swallowing is involuntary and under the control of the cerebral cortex.
B)The pharyngeal stage of deglutition is voluntary.
C)The esophageal stage of swallowing is involuntary.
D)Both B and C are correct.

Answer 3

C

Question 4

Which of the following is not true of enzymes?

A)They accelerate chemical reactions.
B)They change chemically and are in the end products of the reaction.
C)They are vital to chemical reactions.
D)Many contain vitamins in their structure.

Question 5

Which of the following is not one of the openings that must be blocked when food moves from the pharynx into the esophagus?

A)Oropharynx
B)Nasopharynx
C)Larynx
D)Mouth

Question 6

The process of swallowing is known as:

A)mastication.
B)deglutition.
C)peristalsis.
D)segmentation.

Question 7

Polysaccharides are hydrolyzed into disaccharides by enzymes known as:

A)lipase.
B)proteases.
C)maltase.
D)amylase.

Question 8

The major final product that results from the digestion of carbohydrates is:

A)glucose.
B)sucrose.
C)lactose.
D)maltose.

Question 9

The enzyme pepsin begins the digestion of:

A)carbohydrates.
B)protein.
C)fat.
D)nucleic acids.

Question 10

Which of the following is not a property of enzymes?

A)Most enzymes catalyze a chemical reaction in only one direction.
B)Enzymes function optimally at a specific pH.
C)Many enzymes are synthesized as inactive proenzymes or zymogens.
D)Enzyme action can be inhibited or inactivated by various physical and chemical agents that change the shape of enzyme molecules.

Question 11

Which of the processes of mechanical digestion involves the esophagus?

A)Deglutition
B)Peristalsis
C)Churning
D)Both A and B

Question 12

Hydrolysis refers to:

A)breaking down a molecule of water to hydrogen and oxygen gas.
B)using water to split larger compounds into smaller ones.
C)using water to build larger compounds from smaller ones.
D)none of the above.

Question 13

Which step of deglutition is under voluntary control?

A)Oral stage
B)Pharyngeal stage
C)Esophageal stage
D)Gastric phase

Question 14

The enterogastric reflex causes:

A)secretion of digestive enzymes in the small intestine.
B)secretion of digestive enzymes in the stomach.
C)inhibition of gastric peristalsis.
D)acceleration of gastric peristalsis.

Question 15

Which of the following is a disaccharide?

A)Glucose
B)Starch
C)Sucrose
D)Glycogen

Question 16

An end product of fat digestion is:

A)glycerol.
B)glucose.
C)glycogen.
D)galactose.

Question 17

When classified according to the kind of chemical reactions catalyzed, digestive enzymes are referred to as _____ enzymes.

A)oxidation-reduction
B)hydrolyzing
C)phosphorylating
D)hydrase

Question 18

The process of fat emulsification consists of:

A)chemically breaking down fat molecules.
B)the secretion of digestive juices for fat digestion.
C)absorption of fats.
D)breaking fats into small droplets.

Question 19

Structurally, enzymes are:

A)lipids.
B)carbohydrates.
C)proteins.
D)inorganic compounds.

Question 20

The hormone that inhibits gastric muscle, slowing passage of food into the duodenum, is called:

A)gastric inhibitory peptide.
B)enterogastrone.
C)chyme.
D)cholecystokinin.

Question 21

Glucose moves from the GI tract into the circulatory system by the process of:

A)diffusion.
B)cotransport.
C)facilitated diffusion.
D)filtration.

Question 22

An end product of the action of the enzyme phospholipase is:

A)colipase.
B)a triglyceride.
C)a free fatty acid.
D)both B and C.

Question 23

The hormone that stimulates the gallbladder to release bile is:

A)enterogastrone.
B)insulin.
C)gastrin.
D)cholecystokinin.

Question 24

Which of the following does not cause a decrease in gastric peristalsis?

A)The release of GIP
B)Increased deglutition
C)Acid in the duodenum
D)Distention of the duodenum

Question 25

Cellulose is a residue of digestion that comes from:

A)carbohydrates.
B)meat proteins.
C)undigested fats.
D)undigested connective tissue.

Question 26

Which of the following is not a barrier to the absorption of glucose?

A)Size of the molecule
B)The molecule's hydrophilia
C)The molecule's hydrophobia
D)Cell membrane's high concentration of lipids

Question 27

Which phase(s) of gastric secretion is(are) stimulated by the sight, taste, and smell of food?

A)Intestinal phase
B)Cephalic phase
C)Gastric phase
D)All of the above

Question 28

The enzyme amylase functions best in a _____ pH.

A)slightly acid
B)slightly base
C)neutral
D)Both A and C are correct.

Question 29

Chylomicrons are formed to facilitate the transport of:

A)amino acids.
B)fats.
C)glucose.
D)vitamins.

Question 30

Which of the following is not true of segmentation?

A)It moves food back and forth in one segment of the GI tract.
B)It moves food through the GI tract.
C)It facilitates absorption.
D)It mixes food with digestive juices.

Question 31

Which blood vessel carries absorbed food from the GI tract to the liver?

A)Hepatic artery
B)Hepatic vein
C)Portal vein
D)Renal artery

Question 32

The hormone thought to be a messenger causing release of digestive enzymes from the intestinal mucosa is:

A)vasoactive intestinal peptide.
B)enterogastrone.
C)secretin.
D)cholecystokinin-pancreozymin.

Question 33

The major site for the absorption of the end products of digestion is the:

A)stomach.
B)small intestine.
C)cecum.
D)large intestine.

Question 34

The substances absorbed into the lymph capillaries are:

A)glycerol and fatty acids.
B)glucose and glycerol.
C)amino acids and fatty acids.
D)glucose and amino acids.

Question 35

The intestinal hormone cholecystokinin:

A)causes the pancreas to increase exocrine secretions high in enzyme content.
B)opposes the influence of gastrin on gastric parietal cells.
C)stimulates the contraction of the gallbladder.
D)does all of the above.

Question 36

Rotavirus can cause what life-threatening condition in infants?

A)Constipation
B)Diarrhea
C)Cholera
D)Pyloric stenosis

Question 37

The hormone that stimulates the release of bicarbonate substance from the pancreas is:

A)enterogastrone.
B)secretin.
C)gastrin.
D)cholecystokinin-pancreozymin.

Question 38

Bicarbonates are useful in the GI tract to:

A)neutralize hydrochloric acid.
B)break down fats.
C)activate secretin.
D)activate pepsin.

Question 39

Which of these is not an example of mechanical digestion?

A)Moistening the food
B)Changing food from large to small particles
C)Propelling food through the digestive tract
D)All of the above are examples of mechanical digestion.

Question 40

The sodium cotransport or coupled transport acts to transport sodium ions and glucose molecules _____ the GI lumen.

A)passively out of
B)passively into
C)actively out of
D)actively into

Question 41

Digestion uses the following methods in which order to accomplish its function?

A)Ingestion, absorption, secretion
B)Ingestion, secretion, absorption
C)Absorption, secretion, ingestion
D)Absorption, ingestion, secretion

Question 42

Pancreatic juice contains all of the following substances except:

A)chymotrypsin.
B)nucleases.
C)amylase.
D)pepsinogen.

Question 43

Contact digestion occurs in which location in the digestive system?

A)Mouth
B)Esophagus
C)Stomach
D)Small intestine

Question 44

Which of the following structures is not used to block an opening during swallowing?

A)Glottis
B)Epiglottis
C)Soft palate and uvula
D)Tongue

Question 45

Saliva contains all of the following substances except:

A)amylase.
B)lipase.
C)intrinsic factor.
D)mucus.

Question 46

The disaccharide lactose is made up of which two saccharide units?

A)Glucose and glucose
B)Glucose and fructose
C)Glucose and galactose
D)None of the above

Question 47

Which of the following works with gastric inhibitory peptide to inhibit gastric peristalsis?

A)Retropulsion
B)Cholecystokinin
C)The enterogastric reflex
D)Both B and C

Question 48

The most important function of the digestive system is:

A)elimination.
B)absorption.
C)motility.
D)secretion.

Question 49

The first phase of deglutition or swallowing occurs in the:

A)pharynx.
B)larynx.
C)esophagus.
D)None of the above are correct.

Question 50

Gastric juice contains all of the following substances except:

A)intrinsic factor.
B)enterokinase.
C)hydrochloric acid.
D)pepsin.

Question 51

Which of the following protein-digesting enzymes is made in the stomach?

A)Trypsin
B)Chymotrypsin
C)Pepsin
D)Peptidase

Question 52

Pancreatic juice contains all of the following substances except:

A)amylase.
B)trypsinogen.
C)enterokinase.
D)lipase.

Question 53

Which of the following is not a digestive enzyme for lipids?

A)Bile
B)Lipase
C)Phospholipase
D)All of the above are digestive enzymes for lipids.

Question 54

Segmentation is different from peristalsis because:

A)segmentation only occurs in the stomach.
B)it is a type of mechanical digestion.
C)it does not move food through the digestive tract.
D)there is no difference between segmentation and peristalsis.

Question 55

Bile contains all of the following substances except:

A)bile salts.
B)lecithin.
C)amylase.
D)bilirubin.

Question 56

The disaccharide sucrose is made up of which two saccharide units?

A)Glucose and glucose
B)Glucose and fructose
C)Glucose and galactose
D)None of the above

Question 57

The disaccharide maltose is made up of which two saccharide units?

A)Glucose and glucose
B)Glucose and fructose
C)Glucose and galactose
D)None of the above

Question 58

The process of emulsification is important in the digestion of:

A)proteins.
B)fats.
C)polysaccharides.
D)disaccharides.

Question 59

Which monosaccharide is found in all three of the most common disaccharides?

A)Fructose
B)Glucose
C)Galactose
D)Levulose

Question 60

Which of the following is not a stage in deglutition?

A)Gastric
B)Oral
C)Pharyngeal
D)Esophageal

Question 61

Chemical digestion can be defined as all of the changes in chemical composition that food undergoes as it travels through the digestive tract.

Question 62

Peristalsis is a back-and-forth action that breaks apart chunks of food and mixes in digestive juices.

Question 63

Which of the following best describes the enzymatic role in carbohydrate digestion?

A)Amylase, sucrase, lactase, and maltase catalyze the breakdown of carbohydrates to glucose.
B)Pepsin, trypsin, chymotrypsin, and peptidase catalyze the breakdown of carbohydrates to glucose.
C)Amylase, peptidase, sucrase, and chymotrypsin catalyze the breakdown of carbohydrates to glucose.
D)Lecithin mixes with water to catalyze the breakdown of carbohydrates to glucose.

Question 64

Enzymes are unique in that they can function optimally within a wide range of pH.

Question 65

The enzyme amylase is produced by the:

A)stomach.
B)pancreas.
C)salivary glands.
D)Both B and C are correct.

Question 66

After the absorption of a large meal, high levels of chylomicrons would be found in the:

A)lacteals of the villi.
B)blood in the inferior vena cava.
C)blood in the hepatic portal system.
D)Both A and C are correct.

Question 67

After the absorption of a large meal, high levels of glucose and amino acids would be found in the:

A)lacteals of the villi.
B)blood of the inferior vena cava.
C)blood in the hepatic portal system.
D)Both A and C are correct.

Question 68

After leaving the stomach, chyme normally takes about 5 hours to pass all the way through the small intestine.

Question 69

Which statement best explains the process of absorption?

A)Absorption is the process of taking food into the mouth and starting it on its journey through the digestive tract.
B)Absorption releases digestive juices (containing enzymes, acids, bases, mucus, bile, or other products that facilitate digestion).
C)Absorption is the movement by the muscular components of the digestive tube, including processes of mechanical digestion; examples include peristalsis and segmentation.
D)Absorption is the passage of substances (notably digested foods, water, salts, and vitamins) through the intestinal mucosa into the blood or lymph.

Question 70

Amylases are found in saliva and in pancreatic juice.

Question 71

The bolus of food is formed during the pharyngeal stage of deglutition.

Question 72

Why can it be said that absorption is the reason for digestion?

A)Even though digestion includes the processes of mechanical and chemical breakdown of ingested food, the optimum goal of digestion is to absorb nutrients.
B)The absorption process facilitates the emulsification of fats by breaking large fat drops into small droplets.
C)Absorption involves the grinding action of the teeth and the mechanical mixing of food as it passes through the gastrointestinal tract, thus allowing regulation of digestion.
D)Fluid balance, maintenance of core body temperature, numerous circadian rhythms, and regulation of pH and metabolic rates are included as parts of the absorption process.

Question 73

Enzymes are usually defined as inorganic catalysts.

Question 74

The end product of fat digestion is:

A)fatty acids.
B)monoglycerides.
C)glycerol.
D)all of the above.

Question 75

Respiration is inhibited for the 1 to 3 seconds required for food to clear the pharynx during each swallowing.

Question 76

To propel food from the pharynx into the esophagus, three openings must be blocked.

Question 77

The end product of carbohydrate digestion is:

A)glucose.
B)maltose.
C)fructose.
D)sucrose.

Question 78

The parietal cells of the stomach do not produce which of the following?

A)Pepsinogen
B)Hydrochloric acid
C)Intrinsic factor
D)The parietal cell of the stomach produces all of the above.

Question 79

Most enzymes catalyze a chemical reaction in both directions. Which is the best explanation of this statement?

A)Chemical reaction in both directions means the direction and rate of the reaction is being governed by gravity; for example, food in the lower digestive tract is moved by peristalsis, whereas food in the upper part of the digestive tract is moved by segmentation.
B)Chemical reaction in both directions means that enzymes are both intracellular and extracellular, depending on whether they act within cells or outside them in the surrounding medium.
C)Chemical reaction in both directions means the direction and rate of the reaction is being governed by the rate law or law of mass action; for example, slowing of digestion when absorption is interfered with and the products of digestion accumulate.
D)Both B and C are accurate explanations.

Question 80

The process of emptying the stomach takes about 12 hours after a meal.