Question 1

Which of the following best describes the function of surfactant produced by type II alveolar cells in the lungs?

Accepted Answer

It reduces the surface tension within the alveoli, preventing their collapse during exhalation.

Question 2

A patient is diagnosed with a restrictive lung disease. Which of the following pulmonary volumes or capacities would most likely be decreased in this patient?

Accepted Answer

Vital capacity (VC)

Question 3

According to Boyle’s law, what will happen to the pressure inside the lungs if the volume of the thoracic cavity increases during inspiration, assuming temperature and number of gas molecules remain constant?

Accepted Answer

Pressure will decrease.

Question 4

Which of the following equations correctly represents the reaction catalyzed by carbonic anhydrase in erythrocytes during carbon dioxide transport?

Accepted Answer

$$\mathrm{CO_2$ + H_2O \rightarrow H_2CO_3 \rightarrow $$HCO_3$$^- + H^+}$$

Question 5

A person is experiencing hyperventilation. Which of the following changes would you expect to observe in their blood chemistry?

Accepted Answer

Decreased PCO2 and increased blood pH (alkalosis)

Question 6

Which of the following best explains why the right lung has three lobes while the left lung has only two?

Accepted Answer

The left lung has fewer lobes to make space for the heart.

Question 7

A patient with chronic bronchitis, an obstructive lung disease, is likely to have which of the following changes in pulmonary volumes?

Accepted Answer

Increased residual volume (RV) and decreased vital capacity (VC)

Question 8

Which of the following best describes the role of the central chemoreceptors in the regulation of ventilation?

Accepted Answer

They monitor H+ concentration in cerebrospinal fluid and adjust ventilation to maintain blood pH.

Question 9

Which of the following is the correct formula for calculating total lung capacity (TLC)?

Accepted Answer

$$\mathrm{TLC = IRV + TV + ERV + RV}$$

Question 10

A person inhales deeply and then forcibly exhales as much air as possible. Which pulmonary capacity is being measured?

Accepted Answer

Vital capacity

Question 11

Which of the following best explains why oxygen diffuses from the alveoli into the pulmonary capillaries during external respiration?

Accepted Answer

The partial pressure of oxygen is higher in the alveoli than in the pulmonary capillaries.

Question 12

Which of the following is a function of the nasal conchae in the nasal cavity?

Accepted Answer

They create turbulence to filter, warm, and humidify inspired air.

Question 13

A patient has a blood pH of 7.25 and an elevated PCO2. Which respiratory condition is most likely present?

Accepted Answer

Respiratory acidosis

Question 14

Which of the following best describes the effect of increased airway resistance on pulmonary ventilation?

Accepted Answer

It decreases the effectiveness of expiration and may trap air in the alveoli.

Question 15

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

Accepted Answer

Synthesis of plasma proteins for blood clotting

Question 16

A person with a thickened respiratory membrane due to pulmonary fibrosis will most likely experience which of the following?

Accepted Answer

Decreased efficiency of pulmonary gas exchange

Question 17

Which of the following best describes the oxygen-hemoglobin dissociation curve when the partial pressure of oxygen drops from 100 mm Hg to 80 mm Hg?

Accepted Answer

Percent saturation of hemoglobin changes only slightly, allowing continued oxygen loading in the lungs.

Question 18

Which of the following is the primary muscle responsible for increasing the volume of the thoracic cavity during quiet inspiration?

Accepted Answer

Diaphragm

Question 19

Which of the following best describes the role of the pleural fluid?

Accepted Answer

It lubricates the pleural surfaces, allowing smooth movement during breathing.

Question 20

Which of the following is the correct formula for calculating inspiratory capacity (IC)?

Accepted Answer

$$\mathrm{IC = TV + IRV}$$

Chapter 21: The Respiratory System - Anatomy, Physiology, and Clinical Concepts

Study Guide - Practice Questions

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