Deck 15: The Digestive System

Question 1

The enteric nervous system

A) includes the myenteric plexus.
B) includes the submucosal plexus.
C) includes vagal nerve efferents.
D) both (a) and (b) above.
E) both (a) and (c) above.

Answer 1

both (a) and (b) above.

Question 2

Which of the following organs does not produce secretions that are directly involved in chemical digestion?

A) esophagus.
B) stomach.
C) pancreas.
D) small intestine.
E) liver

Answer 2

esophagus.

Question 3

The serosa is the

A) abdominal cavity containing the stomach.
B) blood supply to the stomach.
C) inner lining of the digestive tract.
D) layer of smooth muscle of the digestive tract.
E) outer connective tissue covering of the digestive tract.

Answer 3

outer connective tissue covering of the digestive tract.

Question 4

Fats are digested to

A) amino acids.
B) cellulose.
C) fatty acids and glycerol.
D) fructose.
E) monosaccharides.

Question 5

Which layer of the digestive wall is connective tissue that provided distensibility and elasticity?

A) mucosa
B) submucosa
C) muscular layer
D) serosa
E) myenteric plexus

Question 6

Which of the following statements concerning parasympathetic innervation of the digestive tract is incorrect?

A) in general, parasympathetic stimulation is excitatory to the digestive system.
B) parasympathetic innervation to the digestive tract comes primarily through the vagus nerve.
C) parasympathetic innervation is part of the extrinsic nerve supply to the digestive tract.
D) parasympathetic stimulation of the salivary glands produces a saliva rich in mucus.
E) parasympathetic stimulation increases salivary, gastric, pancreatic, and biliary secretion.

Question 7

Carbohydrates are absorbed as

A) polysaccharides.
B) disaccharides.
C) monosaccharides.
D) amino acids.
E) fatty acids.

Question 8

Mixing movements

A) promote digestion by mixing food with digestive juices.
B) facilitate absorption by exposing luminal contents to absorptive surfaces.
C) take place only in the stomach.
D) promote digestion by mixing food with digestive juices and facilitates absorption by exposing luminal contents to absorptive surfaces.
E) all of these answers.

Question 9

Digestive motility

A) is accomplished by smooth muscle contractions.
B) is accomplished by smooth and voluntary muscle contractions.
C) may be propulsive in nature.
D) both (a) and (b) above.
E) both (a) and (c) above.

Question 10

The wall of the digestive tract contains different types of sensory receptors that:

A) respond to chemical changes
B) respond to mechanical changes
C) respond to temperature changes
D) both (a) and (b)
E) both (a) and (c)

Question 11

9,500 ml of fluid is absorbed from the digestive tract daily. The ultimate source of most of this fluid is

A) food and fluid ingested during meals.
B) stored within secretory cells of the digestive tract.
C) the plasma.
D) the accessory digestive organs.
E) metabolic water.

Question 12

Chewing increases which of the following secretions?

A) salivary secretion.
B) gastric secretion.
C) pancreatic secretion.
D) both (a) and (b) above.
E) all of these answers.

Question 13

Digestion of polysaccharides

A) is accomplished using enzymes.
B) begins in the mouth
C) is finished in the stomach
D) both (a) and (b) above.
E) both (a) and (c) above.

Question 14

Which factor is not involved in the regulation of digestive system function?

A) autonomous smooth muscle function
B) frontal lobe processing
C) smooth muscle function
D) extrinsic nerves
E) hormones

Question 15

Proteins are primarily digested to and absorbed as

A) amino acids.
B) cellulose.
C) fatty acids and glycerol.
D) monosaccharides.
E) vitamins.

Question 16

Which statement regarding control of digestive processes is incorrect?

A) short reflexes influence motility and secretion in localized areas.
B) all elements of the short reflexes are contained within the digestive organ's wall.
C) hormones play a role.
D) osmoreceptors monitor the acidity of the luminal contents.
E) there are stretch receptors in the walls of digestive organs.

Question 17

Digestive secretions include all of the following except:

A) enzymes.
B) bile.
C) mucus.
D) salts
E) vitamins

Question 18

Which is the primary absorptive organ of the digestive system?

A) salivary glands.
B) oral cavity.
C) stomach.
D) small intestine.
E) colon.

Question 19

Which tissue layer provide for primary digestive motility?

A) mucosa.
B) submucosa.
C) muscularis mucosa.
D) muscularis externa.
E) mesentery.

Question 20

The intrinsic nerve plexuses

A) produce spontaneous depolarization of the smooth muscle cells in the wall of the digestive tract.
B) are located in the mucosa.
C) coordinate local activity in the digestive tract.
D) both (a) and (c) above.
E) all of these answers.

Question 21

Which of the following statements concerning the process of salivation is incorrect?

A) salivation is entirely under neural control.
B) parasympathetic stimulation and sympathetic stimulation both increase salivary secretion.
C) the acquired salivary reflex occurs upon stimulation of chemoreceptors and/or pressure receptors in the mouth.
D) parasympathetic stimulation produces a watery saliva rich in enzymes.
E) the salivary center is located in the medulla.

Question 22

Which aspect of gastric motility is associated with receptive relaxation?

A) gastric filling
B) gastric storage
C) gastric mixing
D) gastric emptying

Question 23

As food moves into the esophagus from the mouth:

A) peristaltic contractions move food toward the stomach
B) gravity assists peristaltic contractions to move food toward the stomach
C) smooth muscle contractions end
D) digestive enzymes are secreted by the lining of the esophagus
E) the gastroesophageal sphincter remains closed

Question 24

Gastric mixing

A) occurs primarily in the body of the stomach.
B) occurs as a result of the stomach's contents being tumbled back and forth in the antrum because of vigorous peristaltic contractions.
C) mixes the food with gastric secretions to convert it to a finely divided liquid form known as chyme.
D) both (b) and (c) above.
E) all of these answers.

Question 25

Salivary secretion:

A) is controlled by both conditioned and unconditioned reflexes
B) is controlled only by hormones
C) is controlled only by sympathetic nerves
D) is more watery when stimulated by the sympathetic nerves
E) none of the above

Question 26

Which of the following is accomplished by chewing?

A) grinding and breaking up food
B) mixing food with saliva to facilitate swallowing
C) reflexively increasing salivary, gastric, pancreatic, and bile secretion
D) two of these answers.
E) all of these answers.

Question 27

What prevents food from entering the nasal passages during swallowing?

A) elevation of the uvula
B) contraction of the pharyngeal muscles
C) positioning of the tongue
D) tight apposition of the vocal cords over the glottis
E) elevation of the epiglottis over the nasopharynx

Question 28

The stomach performs all of the following except:

A) stores ingested food
B) secretes HCl
C) secretes enzymes that begin protein digestion
D) converts chewed food into a thick, liquid paste called chyme
E) allows digested material to move quickly into the duodenum

Question 29

During the oropharyngeal phase of swallowing, food is prevented from

A) reentering the mouth by elevation of the uvula, which lodges against the back of the throat.
B) entering the nasal passages by closure of the nasopharyngeal sphincter.
C) entering the trachea primarily by the epiglottis blocking the opening between the vocal cords.
D) more than one of these answers.
E) none of these answers.

Question 30

Digestion in the mouth involves

A) hydrolysis of proteins my amylase
B) absorption of simple sugars
C) hormonal control
D) hydrolysis of polysaccharides by amylase
E) bile actions

Question 31

The gastroesophageal sphincter is normally closed to prevent

A) air from entering the esophagus during.
B) gastric contents from refluxing into the esophagus.
C) vomiting.
D) esophageal leaking into the stomach.
E) food from entering the pharynx.

Question 32

Which of the following is entirely under nervous control and has no hormonal regulatory component?

A) salivary secretion.
B) gastric secretion.
C) pancreatic secretion.
D) liver secretion.
E) all of these answers have a hormonal regulatory component.

Question 33

Which of the following is not a component of saliva?

A) amylase.
B) mucus.
C) pepsin.
D) lysosome.
E) water.

Question 34

Receptive relaxation refers to relaxation of the

A) pharyngoesophageal sphincter during swallowing.
B) pyloric sphincter when the duodenum is prepared to receive the chyme.
C) external anal sphincter when the individual is receptive to the defecation reflex.
D) stomach as it starts to fill, thereby allowing an increase in volume with very little increase in pressure.
E) none of these answers.

Question 35

Which of the following is not a function of saliva? Saliva

A) facilitates swallowing.
B) oral hygiene
C) dissolves glucose to facilitate its absorption by the oral mucosa.
D) has antibacterial action.
E) buffers acids in food

Question 36

What prevents food from entering the trachea during swallowing?

A) elevation of the uvula
B) contraction of the pharyngeal muscles
C) positioning of the tongue
D) tight apposition of the vocal cords over the glottis
E) elevation of the epiglottis over the pharyngoesophageal sphincter

Question 37

The swallowing center is located in the

A) cerebral cortex.
B) medulla.
C) hypothalamus.
D) throat.
E) spinal cord.

Question 38

Swallowing

A) includes the movement of the bolus from the mouth to the stomach.
B) includes only the movement of the bolus from the mouth to the esophagus.
C) is a sequentially programmed, multiple response, all-or-none reflex.
D) both (a) and (c) above.
E) both (b) and (c) above.

Question 39

The major chemical digestive activity occurring in the stomach is

A) digestion of starch.
B) digestion of protein.
C) digestion of fat.
D) absorption of monosaccharides.
E) digestion of vitamins.

Question 40

Which of the following factors will not influence the rate at which a meal will empty from the stomach?

A) fat in the duodenum.
B) acid in the duodenum.
C) caffeine in the duodenum.
D) hypertonicity of the duodenal contents.
E) distention of the duodenum.

Question 41

Which factor below does not slow down gastric activities?

A) enterogastric reflex.
B) entergastrones.
C) secretin.
D) gastrin.
E) cholecystokinin.

Question 42

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

A) toast, orange juice, and coffee.
B) black coffee.
C) fried eggs, bacon, and hash browns.
D) bowl of cereal with skim milk.
E) boiled egg, toast, and juice.

Question 43

Which statement regarding gastric motility and emptying is incorrect?

A) increased fluidity allows more rapid emptying.
B) presence of acid and fat in the stomach initiates the enterogastric reflex.
C) increased gastric volume stimulates motility.
D) vagal activity stimulates motility.
E) distention of the stomach initiates short reflexes.

Question 44

The pyloric sphincter is located between the

A) esophagus and stomach.
B) oral cavity and esophagus.
C) large intestine and rectum.
D) small intestine and large intestine.
E) stomach and small intestine.

Question 45

Hormones acting in the small intestine include

A) secretin and cholecystokinin.
B) secretin and gastrin.
C) cholecystokinin and gastrin.
D) all of these answers.
E) none of these answers.

Question 46

Stomach acid

A) is neutralized in the duodenum.
B) is neutralized with bicarbonate.
C) is neutralized by solutions secreted by the pancreas.
D) both (a) and (b) above.
E) all of these answers.

Question 47

Which of the following factors is the most potent stimulus for inhibition of gastric motility?

A) fat in the duodenum.
B) acid in the duodenum.
C) acid in the stomach.
D) distention of the stomach.
E) hypertonicity of the duodenal contents.

Question 48

Enterogastrones include all of the following except:

A) secretin
B) CCK
C) GIP
D) gastrin
E) all of the above are enterogastrones

Question 49

Which factor is inhibitory to digestive functions?

A) acetylcholine
B) histamine
C) gastrin
D) somatostatin
E) all are stimulatory

Question 50

Which of the following is not secreted by the stomach in response to parasympathetic (acetylcholine) stimulation?

A) pepsinogen
B) HCl
C) gastrin
D) histamine
E) both gastrin and histamine are not secreted in response to parasympathetic stimulation.

Question 51

Which of the following is a precursor to an enzyme that functions in the stomach?

A) pepsinogen
B) HCl
C) intrinsic factor
D) gastrin
E) mucus

Question 52

The parietal cells of the gastric mucosa secrete

A) HCl.
B) pepsinogen.
C) intrinsic factor.
D) both HCl and pepsinogen.
E) both HCl and intrinsic factor.

Question 53

Which of the following statements concerning HCl secretion by the stomach is correct?

A) HCl inactivates salivary amylase
B) HCl activates pepsinogen.
C) provides an acid medium for optimal pepsin activity.
D) denatures proteins
E) all of these answers.

Question 54

The vagus nerve does all of the following except:

A) controls the cephalic phase of gastric secretion
B) stimulates the intrinsic nerve plexus
C) stimulates the release of gastrin
D) inhibits acid secretion by the stomach
E) stimulates pepsinogen secretion

Question 55

Intrinsic factor is

A) secreted by the parietal cells in the stomach.
B) necessary for absorption of vitamin B12.
C) abundant in pernicious anemia.
D) two of these answers.
E) all of these answers.

Question 56

Bile acts in conjunction with:

A) distention of the stomach.
B) gastrin.
C) amylase action
D) lipase action
E) pepsin action

Question 57

Peristaltic antral contractions

A) occur at a rate of 3/min.
B) are responsible for emptying food into the duodenum.
C) are responsible for mixing food and gastric enzymes within the antrum.
D) both (a) and (b) above.
E) all of these answers.

Question 58

During the cephalic phase of gastric secretion,

A) thinking about, seeing, smelling, and chewing food reflexively increases gastric secretion.
B) vagal stimulation of the gastric glands occurs.
C) gastrin is released.
D) both (a) and (b) above.
E) all of these answers.

Question 59

The chief cells of the gastric mucosa secrete

A) bicarbonate ions.
B) HCl.
C) pepsinogen.
D) sucrase.
E) trypsin.

Question 60

Which of the following statements concerning cholecystokinin (CCK) is not correct?

A) it is secreted by the duodenum
B) stimulates the pancreas to secrete digestive enzymes
C) stimulates bile secretion
D) stimulates alkaline buffer secretion by the pancreas
E) slows down stomach emptying

Question 61

Which of the following substances is absorbed by the stomach?

A) glucose.
B) caffeine.
C) aspirin.
D) amino acids.
E) fatty acids.

Question 62

Which of the following stimulates gallbladder contraction?

A) CCK.
B) secretin.
C) sympathetic stimulation.
D) both (a) and (c) above.
E) both (b) and (c) above.

Question 63

The pyloric gland area of the stomach antrum

A) secretes gastrin.
B) is inhibited when gastric pH falls too low.
C) is stimulated by the presence of glucose.
D) both secretes gastrin and is inhibited when the gastric pH falls too low.
E) all of these answers.

Question 64

Which of the following is not a function of the liver?

A) metabolic processing of carbohydrates, proteins, and fats.
B) secretion of proteolytic digestive enzymes.
C) detoxification and/or degradation of body wastes, hormones, drugs, and foreign compounds.
D) synthesis of plasma proteins essential to the clotting process.
E) storage of glycogen, fats, iron, copper, and many vitamins.

Question 65

Which of the following statements about pancreatic enzymes is incorrect?

A) trypsinogen is secreted in an inactive form.
B) pancreatic amylase digests carbohydrate.
C) pancreatic lipase is responsible for triglyceride digestion.
D) except for trypsinogen, other proteolytic enzymes are secreted in active form.
E) trypsinogen is activated by enterokinase.

Question 66

Which vein carries blood into the liver from the digestive tract structures?

A) inferior vena cava
B) superior vena cava
C) hepatic portal vein
D) hepatic vein
E) aorta

Question 67

As food leaves the stomach, gastric secretion is reduced. Which of the following factors does not contribute to this reduction?

A) fat in the duodenum
B) low gastric pH
C) distention of the duodenum
D) high concentration of acid in the stomach or duodenum
E) pepsinogen in the duodenum

Question 68

Which of the following does not occur during vomiting?

A) the diaphragm contracts.
B) the abdominal muscles contract.
C) the stomach contracts.
D) respiration is inhibited.
E) the glottis is closed.

Question 69

During vomiting, the

A) diaphragm contracts.
B) abdominal muscles contract.
C) stomach contracts.
D) both the diaphragm and the abdominal muscles contract.
E) all of these answers.

Question 70

Bile salts

A) aid fat digestion.
B) aid fat absorption through micelle formation.
C) are secreted into the bile.
D) both (a) and (b) above.
E) all of these answers.

Question 71

Which statement regarding control of pancreatic secretion is correct?

A) gastrin stimulates release of neutralization solution.
B) CCK stimulates release of enzymes.
C) secretin stimulates release of bicarbonate.
D) both (a) and (b) above.
E) both (b) and (c) above.

Question 72

After pepsinogen is activated, it

A) autocatalytically activates more pepsinogen.
B) activates the pancreatic proteolytic enzymes in the duodenal lumen after gastric emptying has occurred.
C) inhibits the pyloric gland area in a negative-feedback fashion.
D) both (a) and (b) above.
E) all of these answers.

Question 73

Which of the following accurately describes chymotrypsinogen?

A) chymotrypsinogen is activated by enterokinase.
B) once activated, chymotrypsinogen is involved in protein digestion.
C) chymotrypsinogen is secreted by the endocrine pancreas.
D) all of these answers.
E) none of these answers.

Question 74

Pancreatic exocrine secretions:

A) include CCK and secretin
B) include enzymes for carbohydrate, protein and fat digestion
C) are acidic
D) are regulated by gastrin and GIP
E) include insulin

Question 75

Select the incorrect statement about the pancreas.

A) it has endocrine tissue.
B) it has exocrine tissue.
C) it secretes an alkaline fluid.
D) it secretes pepsinogen.
E) it secretes trypsinogen.

Question 76

The intestinal hormone secretin is released by endocrine cells in the duodenal mucosa in response to

A) distention of the stomach.
B) carbohydrate in the duodenum.
C) acid in the duodenum.
D) gastrin secreted by the pyloric gland area of the stomach.
E) none of these answers.

Question 77

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 stimulates pancreatic enzyme secretion.
C) secretin stimulates the secretion of bicarbonate by the pancreas
D) secretin stimulates the acinar cells.
E) it targets only the stomach

Question 78

Which of the following are functions of aqueous NaHCO₃ secreted by the pancreas into the duodenum?

A) neutralization of acidic gastric contents emptied into the duodenum.
B) prevention of irritation of the duodenal mucosa.
C) active digestion of fat molecules into fatty acids.
D) both (a) and (b) above.
E) all of these answers.

Question 79

Cholecystokinin

A) inhibits stomach emptying
B) stimulates pancreatic enzyme secretion.
C) causes contraction of the gallbladder.
D) both (b) and (c) above.
E) all of these answers.

Question 80

Inhibition of gastric secretion following a meal is accomplished by

A) the enterogastric reflex.
B) inhibition of the pyloric gland area by vagal stimulation.
C) a high concentration of H+, which directly inhibits the release of gastrin.
D) both (a) and (c) above.
E) all of these answers.