Question 1

Which of the following best describes the primary function of the small intestine?

Accepted Answer

Absorption of nutrients and most chemical digestion

Question 2

During the gastric phase of digestion, which of the following events occurs in response to the arrival of food in the stomach?

Accepted Answer

Activation of baroreceptors and chemoreceptors, leading to increased secretion by parietal and chief cells

Question 3

Which equation correctly represents the chemical reaction catalyzed by carbonic anhydrase in parietal cells for hydrochloric acid production?

Accepted Answer

$$CO_2 + H_2O$$ \rightarrow H_2CO_3 \rightarrow $$HCO_3^- + H$$^+$$

Question 4

Which structural adaptation in the small intestine is primarily responsible for increasing the surface area for absorption?

Accepted Answer

Intestinal villi and microvilli

Question 5

A patient with pernicious anemia is most likely deficient in which gastric secretion, and what is its function?

Accepted Answer

Intrinsic factor; aids vitamin B$$_{12}$$ absorption

Question 6

Which phase of swallowing is voluntary and involves the formation of a bolus?

Accepted Answer

Buccal phase

Question 7

Which hormone, produced by the duodenum, stimulates the release of bile from the gallbladder and pancreatic enzymes?

Accepted Answer

Cholecystokinin (CCK)

Question 8

Which of the following is NOT a function of the large intestine?

Accepted Answer

Absorption of most nutrients

Question 9

Which type of muscle tissue is found in the walls of the digestive tract and is responsible for peristalsis?

Accepted Answer

Visceral smooth muscle

Question 10

Which of the following best explains the 'alkaline tide' that occurs after a meal?

Accepted Answer

Release of bicarbonate ions into the blood as parietal cells secrete H$$^+$$ into the stomach

Question 11

Which of the following enzymes is secreted by the pancreas and is responsible for the breakdown of proteins in the small intestine?

Accepted Answer

Trypsin

Question 12

During the intestinal phase of gastric secretion, which of the following occurs?

Accepted Answer

Gastrin production is inhibited and pyloric sphincter contraction increases

Question 13

Which region of the small intestine is primarily responsible for neutralizing acidic chyme from the stomach?

Accepted Answer

Duodenum

Question 14

Which of the following best describes the role of chief cells in the stomach?

Accepted Answer

Secrete pepsinogen, which is activated to pepsin in acidic conditions

Question 15

Which process is defined as the progressive dehydration and compaction of indigestible materials prior to elimination from the body?

Accepted Answer

Compaction

Question 16

Which of the following is a correct sequence of the three phases of gastric secretion?

Accepted Answer

Cephalic phase, gastric phase, intestinal phase

Question 17

Which of the following is a function of the brush border enzymes in the small intestine?

Accepted Answer

Digestion of nutrients at the surface of epithelial cells

Question 18

Which of the following best explains why pancreatic proteolytic enzymes are secreted in inactive forms?

Accepted Answer

To prevent autodigestion of pancreatic tissue

Question 19

Which of the following is a correct description of peristalsis in the digestive tract?

Accepted Answer

Coordinated, wave-like contractions of smooth muscle that propel contents forward

Question 20

Which of the following is a plausible consequence of surgical removal of the jejunum?

Accepted Answer

Decreased chemical digestion and nutrient absorption

Digestive System: Structure, Function, and Regulation

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