Question 1

Which layer of the stomach's muscularis is unique compared to other regions of the digestive tract, and what is its primary function?

Accepted Answer

The oblique layer; it allows the stomach to churn, mix, and physically break down food.

Question 2

During swallowing, which phase is controlled by the medulla and lower pons, and what is its main function?

Accepted Answer

Pharyngeal-esophageal phase; it moves the bolus from the pharynx to the esophagus via peristalsis.

Question 3

Which cells in the gastric glands secrete hydrochloric acid and intrinsic factor, and what is the physiological importance of intrinsic factor?

Accepted Answer

Parietal cells; intrinsic factor is essential for vitamin B$$_{12}$$ absorption.

Question 4

What is the main function of bile salts in digestion?

Accepted Answer

Emulsify fats and facilitate fat and cholesterol absorption.

Question 5

Which anatomical structure controls the passage of chyme from the stomach to the duodenum?

Accepted Answer

Pyloric sphincter

Question 6

What is the primary stimulus for the release of cholecystokinin (CCK) from the duodenum?

Accepted Answer

Acidic, fatty chyme entering the duodenum

Question 7

Which of the following best describes the mucosal barrier of the stomach and its protective mechanisms?

Accepted Answer

A thick coat of bicarbonate-rich mucus, tight junctions between epithelial cells, and rapid replacement of damaged cells.

Question 8

Which phase of gastric secretion is triggered by the sight, smell, or thought of food?

Accepted Answer

Cephalic (reflex) phase

Question 9

What is the effect of antihistamines on gastric secretion?

Accepted Answer

They block H$$_2$$ receptors and decrease hydrochloric acid release.

Question 10

Which structural modification of the small intestine increases its surface area for absorption?

Accepted Answer

Plicae circulares, villi, and microvilli

Question 11

A patient with a deficiency in intrinsic factor would most likely develop which condition?

Accepted Answer

Pernicious anemia due to impaired vitamin B$$_{12}$$ absorption

Question 12

Which cells in the liver are responsible for phagocytosis of bacteria and worn-out blood cells?

Accepted Answer

Kupffer cells

Question 13

What is the main function of the enterogastric reflex?

Accepted Answer

It inhibits gastric secretion and prevents duodenal overfilling.

Question 14

Which of the following best describes the composition and function of bile?

Accepted Answer

Bile is a yellow-green, alkaline solution containing bile salts, pigments, cholesterol, and phospholipids; it emulsifies fats.

Question 15

Which of the following is a correct sequence of events during the swallowing reflex?

Accepted Answer

Bolus is forced into the oropharynx, upper esophageal sphincter relaxes, peristalsis moves bolus down the esophagus.

Question 16

Which region of the stomach is continuous with the duodenum?

Accepted Answer

Pylorus

Question 17

What is the role of the sphincter of Oddi in digestion?

Accepted Answer

It controls the entry of bile and pancreatic juice into the duodenum.

Question 18

Which of the following best explains why carbohydrate-rich chyme empties from the stomach faster than fat-laden chyme?

Accepted Answer

Carbohydrate digestion is quicker, so chyme moves rapidly through the duodenum.

Question 19

Which of the following is NOT a function of hepatocytes?

Accepted Answer

Secretion of pepsinogen

The Digestive System: Anatomy and Physiology Study Notes (Part B)

Study Guide - Practice Questions