Question 1

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

Accepted Answer

Absorption of most nutrients and water

Question 2

Which layer of the alimentary canal is responsible for peristalsis and segmentation?

Accepted Answer

Muscularis externa

Question 3

A patient presents with pernicious anemia. Which of the following is most likely deficient in their stomach?

Accepted Answer

Intrinsic factor

Question 4

Which of the following statements about bile salts is correct?

Accepted Answer

They are cholesterol derivatives that emulsify fats in the small intestine.

Question 5

Which nerve plexus regulates glands and smooth muscle in the mucosa of the GI tract?

Accepted Answer

Submucosal nerve plexus

Question 6

A drug that blocks H2 (histamine) receptors in the stomach would most directly decrease which of the following?

Accepted Answer

HCl secretion

Question 7

Which of the following best explains why fatty chyme remains in the duodenum longer than carbohydrate-rich chyme?

Accepted Answer

Fatty chyme stimulates the enterogastric reflex, slowing gastric emptying.

Question 8

Which of the following is the correct sequence of layers from the lumen outward in the GI tract?

Accepted Answer

Mucosa, submucosa, muscularis externa, serosa

Question 9

Which of the following best describes the role of the hepatic portal vein?

Accepted Answer

It drains nutrient-rich blood from digestive organs to the liver for processing.

Question 10

Which of the following is a function of the large intestine?

Accepted Answer

Fermentation of indigestible carbohydrates by bacteria

Question 11

A patient with a damaged brush border in the small intestine would have the most difficulty digesting which of the following?

Accepted Answer

Proteins and carbohydrates

Question 12

Which hormone stimulates gallbladder contraction and relaxation of the hepatopancreatic sphincter?

Accepted Answer

Cholecystokinin (CCK)

Question 13

Which of the following best describes the absorption of vitamin B12 in the digestive tract?

Accepted Answer

It binds to intrinsic factor and is absorbed in the small intestine by endocytosis.

Question 14

Which of the following is true regarding the regulation of pancreatic secretion?

Accepted Answer

CCK stimulates enzyme-rich juice from acini, while secretin stimulates bicarbonate-rich juice from duct cells.

Question 15

Which of the following is a correct statement about the mucosal barrier in the stomach?

Accepted Answer

It includes a bicarbonate-rich mucus layer and tight junctions between epithelial cells.

Question 16

Which of the following best explains why water absorption in the small intestine is coupled with solute uptake?

Accepted Answer

Net osmosis occurs whenever a concentration gradient is established by active transport of solutes.

Question 17

A patient with celiac disease has damage to which structure, leading to malabsorption?

Accepted Answer

Intestinal villi and brush border

Question 18

Which of the following is the correct pathway for bile salts in enterohepatic circulation?

Accepted Answer

Liver → duodenum → ileum → hepatic portal blood → liver

Question 19

Which of the following best describes the function of Paneth cells in the small intestine?

Accepted Answer

Secrete antimicrobial agents such as defensins and lysozyme

Question 20

Which of the following is a direct effect of sympathetic stimulation on the digestive system?

Accepted Answer

Inhibits secretion and motility

The Digestive System: Structure, Function, and Processes

Study Guide - Practice Questions