Question 1

A patient with severe chest wall deformity is found to have reduced lung compliance. Which of the following best explains how this affects their breathing mechanics?

Accepted Answer

Reduced compliance increases the work required to expand the lungs during inspiration.

Question 2

Which of the following best describes the role of surfactant in the alveoli?

Accepted Answer

It reduces surface tension, preventing alveolar collapse (atelectasis).

Question 3

A premature infant is experiencing respiratory distress due to a lack of surfactant. Which of the following is the most likely consequence?

Accepted Answer

Increased risk of alveolar collapse (atelectasis)

Question 4

During inspiration, which of the following changes occurs according to Boyle’s Law ($$P_1V_1 = P_2V_2$$)?

Accepted Answer

Thoracic volume increases, causing intrapulmonary pressure to decrease.

Question 5

A patient with chronic bronchitis has increased airway resistance. Which of the following is the most direct effect of this change?

Accepted Answer

More effort is required to move air through the bronchi during breathing.

Question 6

Which of the following best explains why CO₂ is the main regulator of breathing under normal conditions?

Accepted Answer

CO₂ levels directly affect blood pH, which is detected by central chemoreceptors.

Question 7

A person is exposed to high altitude, where the partial pressure of oxygen is lower. According to Henry’s Law, what happens to the amount of oxygen dissolved in their blood?

Accepted Answer

It decreases because the partial pressure gradient for oxygen is reduced.

Question 8

Which of the following best describes the Bohr effect in oxygen transport?

Accepted Answer

Increased CO₂ and H⁺ lower hemoglobin’s affinity for O₂, enhancing O₂ release to tissues.

Question 9

Which of the following is the correct sequence of airflow from the nose to the alveoli?

Accepted Answer

Nose → nasal cavity → pharynx → larynx → trachea → bronchi → bronchioles → alveoli

Question 10

A patient with emphysema has destruction of alveolar walls. Which of the following best explains how this affects gas exchange?

Accepted Answer

Decreased surface area reduces the efficiency of pulmonary gas exchange.

Question 11

Which of the following lung volumes is defined as the amount of air remaining in the lungs after a maximal exhalation?

Accepted Answer

Residual Volume (RV)

Question 12

A person is holding their breath after a deep inhalation. Which lung volume is being maximized?

Accepted Answer

Inspiratory Reserve Volume (IRV)

Question 13

Which of the following best describes the main function of the epiglottis during swallowing?

Accepted Answer

It covers the airway to prevent food from entering the trachea.

Question 14

Which of the following is the primary mechanism driving pulmonary (alveolar) gas exchange?

Accepted Answer

Diffusion down partial pressure gradients

Question 15

A patient with severe asthma experiences bronchoconstriction. Which of the following is the most immediate effect on ventilation?

Accepted Answer

Increased airway resistance impairs airflow to the alveoli.

Question 16

Which of the following best explains why residual volume is important for lung function?

Accepted Answer

It prevents lung collapse by maintaining some air in the alveoli after maximal exhalation.

Question 17

Which of the following is the most important stimulus for the central chemoreceptors that regulate breathing?

Accepted Answer

Increased CO₂ levels in the blood

Question 18

A patient with idiopathic pulmonary fibrosis has thickened respiratory membranes. Which of the following best describes the effect on gas exchange?

Accepted Answer

Gas exchange is less efficient due to increased diffusion distance.

Question 19

Which of the following best describes the distribution of oxygen in the blood?

Accepted Answer

About 98% is bound to hemoglobin, and about 2% is dissolved in plasma.

Question 20

Which of the following equations represents the reaction by which the lungs help regulate blood pH?

Accepted Answer

$$\mathrm{CO_2 + H_2O \rightarrow H_2CO_3}$$

Comprehensive Study Notes: The Respiratory System

Study Guide - Practice Questions

Study Guide - Flashcards