Deck 29: A: Physiology of the Digestive System

Question 1

Bile catalyzes the breakdown of fats.

Answer 1

False

Question 2

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

Answer 2

True

Question 3

Enzymes are usually defined as inorganic catalysts.

Answer 3

False

Question 4

Amino acids are the end products of protein digestion.

Question 5

Glycogen and sucrose are examples of polysaccharides.

Question 6

The main glucose-digesting enzyme is glucase.

Question 7

Sucrose is an example of a disaccharide.

Question 8

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

Question 9

Amylases are found in saliva and in pancreatic juice.

Question 10

Large amounts of cool,dilute,or isotonic fluids are best for replacing fluids quickly during exercise.

Question 11

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

Question 12

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

Question 13

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

Question 14

The stimulation of gastric juice secretions occurs in five phases controlled by reflex and chemical mechanisms.

Question 15

Most enzymes are able to work on more than one substance.

Question 16

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

Question 17

The main proteases found in gastric juice are pepsin and trypsin.

Question 18

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

Question 19

Drinking large amounts of water works best as a means of replacing fluids quickly during exercise.

Question 20

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

Question 21

The sodium cotransport,which carries both sodium ions and glucose molecules,is an active transport mechanism.

Question 22

The enterogastric reflex stimulates gastric motility as food enters the duodenum.

Question 23

The only food that can be digested by gastric juice is protein.

Question 24

Vitamins A,D,E,and K depend on bile salts for their absorption.

Question 25

Oral rehydration therapy can be used to replace fluids lost by way of diarrhea.

Question 26

The formation of feces is the primary function of the rectum.

Question 27

Vasoactive intestinal peptide inhibits the production of intestinal juice.

Question 28

Bicarbonates are useful in the GI tract for neutralizing hydrochloric acid.

Question 29

Sucrase hydrolyzes sucrose into glucose and fructose.

Question 30

Paracellular absorption is the absorption of nutrients between cells.

Question 31

Both simple sugars and amino acids are absorbed into the blood in the intestinal capillaries.

Question 32

Diarrhea is one of the leading causes of infant mortality in developing countries.

Question 33

Secretin causes the production of pancreatic fluid high in enzyme content but low in bicarbonate.

Question 34

Chewing and swallowing are both considered mechanical digestion.

Question 35

The process of elimination is simply the expulsion of the residues of digestion from the digestive tract.

Question 36

One of the functions of cholecystokinin is to enhance the influence of gastrin on gastric parietal cells.

Question 37

Vasoactive intestinal peptide inhibits the production of intestinal juice.

Question 38

Salivary glands are stimulated only by olfactory and visual stimuli.

Question 39

Nucleotidase digests nucleotides.

Question 40

Diarrhea occurs when the contents of the lower colon and rectum move at a rate that is slower than normal.

Question 41

The lipase found in saliva is unable to digest much fat because the fat has not been emulsified.

Question 42

The blood surrounding the stomach would have a pH slightly higher than blood in other parts of the body.

Question 43

Mastication is another word for chewing.

Question 44

The pancreatic duct,which connects the pancreas to the small intestines,does not carry the enzyme trypsin.

Question 45

During deglutition,the tongue closes off the nasopharynx.

Question 46

The blood surrounding the pancreas would have a slightly higher pH than blood in other parts of the body.

Question 47

Zymogenic cells secrete enzymes into the lumen of the small intestines.

Question 48

Bile is involved in both secretion and excretion.

Question 49

Chylomicrons are usually not found in the lumen of the small intestine.

Question 50

Peristalsis and segmentation both involve movement of the GI tract.

Question 51

During deglutition,the mouth is closed off by the soft palate and the uvula.

Question 52

Segmentation is described as a wavelike muscle contraction in a hollow organ that moves food through the digestive system.

Question 53

During deglutition,food is denied entry to the larynx by muscle action that causes the epiglottis to block that opening.

Question 54

An enzyme that is a hydrolase breaks water down into hydrogen and oxygen.

Question 55

The involuntary part of swallowing is regulated by the deglutition center of the medulla.

Question 56

Carbohydrates that are used for food are made up of one or more saccharide groups.

Question 57

The primary function of the digestive system is to bring essential nutrients into the internal environment so that they are available to the cells of the body.

Question 58

The action of bile on fat would be an example of mechanical digestion.

Question 59

"Dietary fiber" is a carbohydrate.

Question 60

The stomach releases gastric inhibitory peptide to slow down peristalsis in the duodenum.

Question 61

Enterokinase converts trypsin into trypsinogen.

Question 62

The hydrophilic portion of lecithin is attracted to the exterior water of the micelle.

Question 63

Because enzymes are not changed by the chemical reactions they catalyze,digestive enzymes rarely need to be made.

Question 64

Intestinal motility includes both peristaltic contractions and segmentation.

Question 65

Substances that activate proenzymes are often called kinases.

Question 66

The specificity of enzyme function can be explained by the "key-in-a-lock" mode of action.

Question 67

Enzymes are pH sensitive because differences in the hydrogen ion concentration can affect the shape of the protein molecule.

Question 68

The digestion of triglycerides produces monoglycerides and phospholipids.

Question 69

The process of emulsification is important because it facilitates a greater contact area for the digestion of fat.

Question 70

When fat combines with magnesium,it becomes indigestible.

Question 71

Because acid would be harmful to enzymes,the salivary glands produce bicarbonate ions to lower the pH of saliva.

Question 72

One important role of the salivary glands is the production of mucus,because they are the only glands that produce it.

Question 73

Because trypsin works in the small intestine,its optimal pH must be less than that of pepsin,which works in the stomach.

Question 74

Hydrochloric acid converts pepsinogen into pepsin.

Question 75

Lysophosphatide is a possible end product of fat digestion.

Question 76

Most enzymes in the body are intracellular.

Question 77

Lipase can be called a hydrolase.

Question 78

The hydrophilic portion of lecithin is attracted to the interior fat of the micelle.

Question 79

Enterokinase is converted to trypsinogen by trypsin.

Question 80

Colipase is a substance made by the small intestine,and it functions as a coenzyme in fat digestion.