Question 1

Which of the following best describes the function of the mucosa layer in the alimentary canal?

Accepted Answer

It secretes enzymes and hormones, absorbs products of digestion, and protects against infectious disease.

Question 2

A patient presents with severe abdominal pain and is diagnosed with peritonitis. Which of the following is the most likely cause of this condition?

Accepted Answer

Inflammation of the peritoneum due to infection from a ruptured appendix.

Question 3

Which nerve plexus is primarily responsible for controlling the motility of the gastrointestinal tract?

Accepted Answer

Myenteric nerve plexus

Question 4

During the process of mastication, which muscles are primarily involved in holding food between the teeth?

Accepted Answer

Buccinator and orbicularis oris

Question 5

Which of the following best explains why intrinsic factor is essential for life?

Accepted Answer

It is required for the absorption of vitamin B$_{12}$, which is necessary for the maturation of red blood cells.

Question 6

A patient with chronic heartburn is found to have a hiatal hernia. Which anatomical abnormality is most likely present?

Accepted Answer

The stomach has protruded above the diaphragm.

Question 7

Which of the following is a correct sequence of the layers (tunics) of the alimentary canal from innermost to outermost?

Accepted Answer

Mucosa, submucosa, muscularis externa, serosa

Question 8

Which of the following best describes the role of chief cells in the gastric glands?

Accepted Answer

They secrete pepsinogen, an inactive enzyme that is converted to pepsin.

Question 9

Which equation best represents the conversion of pepsinogen to pepsin in the stomach?

Accepted Answer

$\mathrm{Pepsinogen} + \mathrm{HCl} \rightarrow \mathrm{Pepsin}$

Question 10

Which of the following is a function of saliva in the oral cavity?

Accepted Answer

It initiates the breakdown of starch by amylase.

Question 11

A patient with pernicious anemia is most likely deficient in which of the following?

Accepted Answer

Vitamin B$_{12}$ due to lack of intrinsic factor.

Question 12

Which of the following best describes the difference between intraperitoneal and retroperitoneal organs?

Accepted Answer

Intraperitoneal organs are completely surrounded by peritoneum, while retroperitoneal organs are located posterior to the peritoneum.

Question 13

Which of the following is a consequence of untreated gingivitis?

Accepted Answer

Destruction of periodontal ligament and bone, leading to tooth loss.

Question 14

Which of the following best explains the role of the enteric nervous system in digestion?

Accepted Answer

It provides local control of motility and secretion independent of the central nervous system.

Question 15

Which of the following is absorbed directly into the blood from the stomach?

Accepted Answer

Alcohol and aspirin

Question 16

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

Accepted Answer

It consists of a two-layer coat of alkaline mucus that traps bicarbonate-rich fluid beneath it.

Question 17

Which of the following best describes the process of deglutition (swallowing)?

Accepted Answer

It involves coordinated contraction of the tongue, soft palate, pharynx, and esophagus.

Question 18

Which of the following ions is NOT a major component of saliva?

Accepted Answer

$\mathrm{Ca}^{2+}$

Question 19

Which of the following is the correct formula for the pH range of gastric juice in the stomach?

Accepted Answer

$1.5 - 3.5$

Digestive System: Structure, Function, and Regulation

Study Guide - Practice Questions