Question 1

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

Accepted Answer

It reduces the surface tension of the alveolar fluid, preventing alveolar collapse during exhalation.

Question 2

A patient is experiencing difficulty breathing due to an allergic reaction. Which physiological process is most likely occurring in their bronchioles?

Accepted Answer

Bronchoconstriction due to parasympathetic activation and histamine release.

Question 3

According to Boyle’s Law, what happens to the pressure inside the lungs when the volume of the thoracic cavity increases during inhalation?

Accepted Answer

Pressure decreases, causing air to flow into the lungs.

Question 4

Which of the following equations correctly represents Boyle’s Law as it applies to pulmonary ventilation?

Accepted Answer

$$P = \frac{1}{V}$$

Question 5

A person inhales 500 mL of air, but only 350 mL reaches the alveoli. What is the volume of the anatomic dead space?

Accepted Answer

150 mL

Question 6

Which of the following structures is NOT part of the lower respiratory system?

Accepted Answer

Pharynx

Question 7

During quiet breathing, which muscles are primarily responsible for inspiration?

Accepted Answer

Diaphragm and external intercostal muscles

Question 8

Which of the following best explains why pneumonia can severely impair gas exchange in the lungs?

Accepted Answer

It causes fluid to leak into the alveoli, increasing the diffusion distance for gases.

Question 9

A patient is diagnosed with a pneumothorax. Which of the following best describes what has occurred?

Accepted Answer

Air has entered the pleural cavity, causing the lung to collapse.

Question 10

Which of the following statements about hemoglobin is correct?

Accepted Answer

Hemoglobin saturation increases as PO2 increases, but the relationship is sigmoidal, not linear.

Question 11

Which of the following changes would shift the oxygen–hemoglobin saturation curve to the right, promoting oxygen release to tissues?

Accepted Answer

Increased temperature

Question 12

Which of the following best describes the role of the dorsal respiratory group (DRG) in the medulla oblongata?

Accepted Answer

It functions in both quiet and forced breathing, primarily controlling inspiration.

Question 13

A person is exposed to carbon monoxide (CO). What is the primary danger of CO exposure in terms of respiratory physiology?

Accepted Answer

CO binds to hemoglobin more strongly than O2, reducing oxygen transport.

Question 14

Which of the following is a correct calculation for vital capacity (VC) using pulmonary volumes?

Accepted Answer

$$VC = ERV + VT + IRV$$

Question 15

According to Henry’s Law, what determines the amount of a gas that will dissolve in a liquid at a given temperature?

Accepted Answer

The partial pressure of the gas and its solubility in the liquid

Question 16

Which of the following best explains why CO2 is transported in the blood primarily as bicarbonate ions?

Accepted Answer

The conversion to bicarbonate allows more CO2 to be carried in the plasma without affecting blood pH as much.

Question 17

Which of the following would most likely result in an increase in respiratory rate?

Accepted Answer

An increase in arterial PCO2 (hypercapnia)

Question 18

Which of the following is a function of the pleural fluid?

Accepted Answer

It lubricates the space between the parietal and visceral pleura, allowing smooth lung movement.

Question 19

A 65-year-old lifelong smoker is found to have reduced vital capacity and increased residual volume. Which age-related change is most likely responsible for these findings?

Accepted Answer

Deterioration of elastic tissue in the lungs

Question 20

Which of the following best describes the difference between external and internal respiration?

Accepted Answer

External respiration is the exchange of gases between blood and alveolar air; internal respiration is the uptake of O2 and release of CO2 by cells.

Chapter 23: The Respiratory System – Structure, Function, and Regulation

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