Deck 29: B: Physiology of the Digestive System

Question 1

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 1

C

Question 2

Which of the processes of mechanical digestion involves the esophagus?

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

Answer 2

D

Question 3

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

Answer 3

B

Question 4

The process of swallowing is known as:

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

Question 5

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 6

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.

Question 7

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 8

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 9

Polysaccharides are hydrolyzed into disaccharides by enzymes known as:

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

Question 10

The final product of carbohydrate digestion is a:

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

Question 11

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

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

Question 12

Structurally,enzymes are:

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

Question 13

Which of the following is a disaccharide?

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

Question 14

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 15

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 16

The enzyme pepsin begins the digestion of:

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

Question 17

An end product of fat digestion is:

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

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

Which step of deglutition is under voluntary control?

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

Question 20

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 21

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 22

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 23

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 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

Bicarbonates are useful in the GI tract to:

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

Question 26

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 27

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

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

Question 28

Rotavirus can cause what life-threatening condition in infants?

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

Question 29

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 30

The hormone that stimulates the gallbladder to release bile is:

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

Question 31

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 32

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

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

Question 33

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 34

Cellulose is a residue of digestion that comes from:

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

Question 35

Chylomicrons are formed to facilitate the transport of:

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

Question 36

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 37

The enzyme amylase functions best in a _____ pH.

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

Question 38

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 39

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 40

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 41

Gastric juice contains all of the following substances except:

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

Question 42

The first phase of deglutition or swallowing occurs in the:

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

Question 43

Pancreatic juice contains all of the following substances except:

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

Question 44

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 45

Saliva contains all of the following substances except:

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

Question 46

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 47

Contact digestion occurs in which location in the digestive system?

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

Question 48

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 49

Bile contains all of the following substances except:

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

Question 50

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 51

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 52

The most important function of the digestive system is:

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

Question 53

The process of emulsification is important in the digestion of:

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

Question 54

Which of the following is not a stage in deglutition?

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

Question 55

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

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

Question 56

Pancreatic juice contains all of the following substances except:

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

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

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 59

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

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

Question 60

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 61

Match each primary mechanism of the digestive system with its corresponding definition.
a.Motility
b.Ingestion
c.Elimination
d.Secretion
e.Digestion
f.Absorption
process of taking food into the mouth,starting it on its journey through the digestive tract

Question 62

Match each primary mechanism of the digestive system with its corresponding definition.
a.Motility
b.Ingestion
c.Elimination
d.Secretion
e.Digestion
f.Absorption
movement of digested nutrients through the GI mucosa and into the internal environment

Question 63

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 64

Match each of the digestive juices and enzymes with its corresponding description.
a.Amylase
b.Bile
c.Lactase
d.Maltase
e.Pepsin
f.Peptidase
g.Sucrase
h.Trypsin
i.Lipase
enzyme that works on starch

Question 65

The end product of lipase digestion is:

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

Question 66

Match each primary mechanism of the digestive system with its corresponding definition.
a.Motility
b.Ingestion
c.Elimination
d.Secretion
e.Digestion
f.Absorption
release of digestive juices; release of endocrine hormones that regulate digestion or metabolism of nutrients

Question 67

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 68

Match each phase of gastric secretion with its corresponding statement or definition.
a.Cephalic phase
b.Gastric phase
c.Intestinal phase
phase that is controlled by the entrance of acidic chyme into the duodenum

Question 69

Match each primary mechanism of the digestive system with its corresponding definition.
a.Motility
b.Ingestion
c.Elimination
d.Secretion
e.Digestion
f.Absorption
a group of processes that breaks complex nutrients into simpler ones,thus facilitating their absorption (includes both mechanical and chemical processes)

Question 70

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 71

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 72

The end product of amylase digestion is:

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

Question 73

Match each phase of gastric secretion with its corresponding statement or definition.
a.Cephalic phase
b.Gastric phase
c.Intestinal phase
phase that responds to taste,smell,thoughts of food,and sensations of chewing and swallowing

Question 74

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 75

Match each primary mechanism of the digestive system with its corresponding definition.
a.Motility
b.Ingestion
c.Elimination
d.Secretion
e.Digestion
f.Absorption
excretion of the residues of the digestive process (feces)from the rectum,through the anus; defecation

Question 76

Match each primary mechanism of the digestive system with its corresponding definition.
a.Motility
b.Ingestion
c.Elimination
d.Secretion
e.Digestion
f.Absorption
movement by the muscular components of the digestive tube,including processes of mechanical digestion; examples include peristalsis and segmentation

Question 77

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 78

Match each phase of gastric secretion with its corresponding statement or definition.
a.Cephalic phase
b.Gastric phase
c.Intestinal phase
phase that is initiated by the presence of food in the stomach

Question 79

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 80

The enzyme amylase is produced by the:

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