Question 1

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

Accepted Answer

It decreases surface tension, making it easier for alveoli to expand during inspiration.

Question 2

A patient presents with a stab wound that has opened the pleural cavity to the external environment. Which of the following is most likely to occur?

Accepted Answer

Alveolar pressure equilibrates with intrapleural pressure, resulting in lung collapse (pneumothorax).

Question 3

According to Boyle’s Law, what happens to the pressure of a gas if the volume of its container is halved, assuming temperature remains constant?

Accepted Answer

Pressure is doubled.

Question 4

Which of the following equations correctly represents the relationship described by Fick’s Law of diffusion?

Accepted Answer

$$\Delta M = \frac{DA(C_2$ - C_1$)}{L \Delta t}$$

Question 5

During exercise, which muscles are primarily responsible for forced expiration?

Accepted Answer

Latissimus dorsi, rectus abdominis, transverse abdominis, obliques, and internal intercostals

Question 6

A patient with chronic obstructive pulmonary disease (COPD) is likely to experience which of the following acid-base disturbances?

Accepted Answer

Respiratory acidosis due to reduced alveolar ventilation and increased CO2

Question 7

Which of the following best explains why the right primary bronchus is more likely to be obstructed by a foreign object?

Accepted Answer

It is wider, shorter, and more vertical than the left bronchus.

Question 8

Which of the following statements about the oxygen-hemoglobin dissociation curve is correct?

Accepted Answer

An increase in temperature shifts the curve to the right, decreasing hemoglobin's affinity for oxygen.

Question 9

Which of the following is NOT a function of the respiratory system?

Accepted Answer

Production of insulin

Question 10

A patient is hyperventilating due to anxiety. What changes in plasma pH and CO2 would you expect?

Accepted Answer

Plasma CO2 decreases, plasma pH increases (alkalosis)

Question 11

Which of the following lung volumes cannot be measured directly by spirometry?

Accepted Answer

Residual Volume (RV)

Question 12

Which equation correctly calculates alveolar ventilation ($$V_A) $$given tidal volume ($$V_T$$), anatomical dead space ($$V_D$$), and breathing frequency ($$f$$)?

Accepted Answer

$$V_A = f(V_T - V_D)$$

Question 13

Which of the following best describes the effect of histamine during a severe allergic reaction in the lungs?

Accepted Answer

Histamine causes contraction of bronchiolar smooth muscle, increasing airway resistance.

Question 14

Which of the following is the correct formula for lung compliance ($$C_L$$)?

Accepted Answer

$$C_L = \frac{\Delta V_L}{\Delta P_L}$$

Question 15

Which of the following is true regarding the transport of carbon dioxide in the blood?

Accepted Answer

Most CO2 is transported as bicarbonate ion in plasma.

Question 16

A patient with anemia will have which of the following changes in oxygen transport?

Accepted Answer

Decreased hemoglobin, decreased O2 content, decreased O2 carrying capacity

Question 17

Which of the following best describes the Hering-Breuer reflex?

Accepted Answer

It prevents over-inflation of the lungs by terminating inspiration when stretch receptors are stimulated.

Question 18

Which of the following is the correct formula for minute ventilation ($$V_M$$)?

Accepted Answer

$$V_M = V_T 	imes 	ext{rate}$$

Question 19

Which of the following best explains why the lower regions of the lung ventilate better than the upper regions?

Accepted Answer

The lower regions are more compliant and have more room to expand.

Question 20

Which of the following is the correct formula for vital capacity (VC)?

Accepted Answer

$$VC = IRV + TV + ERV$$

Comprehensive Study Notes: The Respiratory System

Study Guide - Practice Questions

Study Guide - Flashcards