Question 1

Which layer of the esophagus is responsible for peristaltic movement, and what is its composition along the length of the esophagus?

Accepted Answer

The muscularis externa; skeletal muscle superiorly, mixed in the middle, smooth muscle inferiorly

Question 2

During the process of deglutition, which phase is voluntary and what is its primary action?

Accepted Answer

Buccal phase; contraction of the tongue to force the bolus into the oropharynx

Question 3

What is the main function of the gastroesophageal (cardiac) sphincter?

Accepted Answer

To prevent acid reflux by keeping the cardial orifice closed when food is not being swallowed

Question 4

A patient presents with heartburn after a large meal. Which physiological mechanism is most likely responsible for their symptoms?

Accepted Answer

Regurgitation of stomach acid into the esophagus due to relaxation of the gastroesophageal sphincter

Question 5

Which of the following best describes the transition of epithelial tissue at the esophagus-stomach junction?

Accepted Answer

Stratified squamous epithelium changes to simple columnar epithelium

Question 6

Which cell type in the gastric glands secretes hydrochloric acid and intrinsic factor, and what is the importance of intrinsic factor?

Accepted Answer

Parietal cells; intrinsic factor is required for vitamin B12 absorption

Question 7

Which of the following is a direct result of the alkaline tide that occurs during hydrochloric acid secretion in the stomach?

Accepted Answer

Increased bicarbonate ($$\mathrm{$$HCO_3$$^-}) in $$blood leaving the stomach

Question 8

A patient with pernicious anemia is most likely deficient in which gastric secretion, and what is the physiological consequence?

Accepted Answer

Intrinsic factor; impaired absorption of vitamin B12 leading to defective red blood cell maturation

Question 9

Which hormone is released by enteroendocrine cells in response to partially digested proteins in the stomach, and what is its effect?

Accepted Answer

Gastrin; stimulates parietal cells to secrete HCl

Question 10

Which of the following best explains why fatty chyme slows gastric emptying?

Accepted Answer

Fatty chyme stimulates the release of enterogastrones, which inhibit gastric motility

Question 11

Which of the following is NOT a function of hepatocytes in the liver?

Accepted Answer

Secretion of digestive enzymes into the duodenum

Question 12

What is the primary function of bile salts in digestion?

Accepted Answer

Emulsify fats to increase surface area for lipase action

Question 13

Which structure stores and concentrates bile, and what is a common clinical consequence of its dysfunction?

Accepted Answer

Gallbladder; formation of gallstones (biliary calculi)

Question 14

Which enzyme activates trypsinogen to trypsin in the small intestine, and what is the significance of this activation?

Accepted Answer

Enteropeptidase; trypsin then activates other pancreatic proteases

Question 15

A patient with a blocked common bile duct would have difficulty digesting which type of nutrient, and why?

Accepted Answer

Lipids; bile is required for fat emulsification and absorption

Question 16

Which of the following best describes the role of the enterogastric reflex?

Accepted Answer

Inhibits gastric secretion and motility when the duodenum is distended or acidic

Question 17

Which of the following is a consequence of excessive vomiting?

Accepted Answer

Metabolic alkalosis due to loss of stomach acid

Question 18

Which of the following is the only stomach function essential to life?

Accepted Answer

Secretion of intrinsic factor for vitamin B12 absorption

Question 19

Which of the following best explains why the stomach has an additional oblique muscle layer in its muscularis externa?

Accepted Answer

To enhance the churning, mixing, and physical breakdown of food

Question 20

Which clinical condition is most commonly caused by Helicobacter pylori infection, and what is a potential complication if left untreated?

Accepted Answer

Peptic (gastric) ulcer; risk of peritonitis and hemorrhage

Digestive System: Pharynx, Esophagus, Stomach, and Accessory Organs

Study Guide - Practice Questions