Question 1

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

Accepted Answer

It reduces surface tension, preventing alveolar collapse after exhalation.

Question 2

A patient with a genetic disorder produces insufficient surfactant. Which of the following is the most likely consequence?

Accepted Answer

Collapse of alveoli after each exhalation, leading to respiratory distress.

Question 3

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

Accepted Answer

The pressure is halved. $$P = \frac{1}{V}$$

Question 4

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

Accepted Answer

Pharynx

Question 5

During an asthma attack, which of the following occurs in the bronchioles?

Accepted Answer

Bronchoconstriction due to excessive smooth muscle stimulation.

Question 6

Which of the following best explains why breathing through the nose is preferable to breathing through the mouth?

Accepted Answer

The nasal mucosa warms and humidifies inhaled air, protecting lower respiratory structures.

Question 7

A patient is exposed to carbon monoxide (CO). What is the primary danger of CO exposure at the level of hemoglobin?

Accepted Answer

CO binds strongly to hemoglobin, displacing oxygen and reducing oxygen delivery to tissues.

Question 8

Which of the following changes would shift the oxygen–hemoglobin saturation curve to the right, resulting in more oxygen being released to tissues?

Accepted Answer

Increased temperature and decreased pH.

Question 9

Which of the following equations correctly represents the reversible binding of oxygen to hemoglobin?

Accepted Answer

$$\mathrm{Hb} + 4\mathrm{O}_2 \rightleftharpoons \mathrm{HbO}_8$$

Question 10

A person is hyperventilating due to anxiety. What is the most likely effect on arterial PCO2 and blood pH?

Accepted Answer

Arterial PCO2 decreases and blood pH increases.

Question 11

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 inhalation by stimulating inspiratory muscles.

Question 12

Which of the following is a direct result of a pneumothorax?

Accepted Answer

Collapse of the affected lung due to loss of negative intrapleural pressure.

Question 13

A patient with pneumonia has fluid accumulation in the alveoli. Which of the following best explains how this affects gas exchange?

Accepted Answer

It increases the distance for diffusion, reducing the efficiency of gas exchange.

Question 14

Which of the following best describes the relationship between pulmonary ventilation and atmospheric pressure?

Accepted Answer

Air flows from an area of higher pressure to an area of lower pressure.

Question 15

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

Accepted Answer

$$VC = ERV + VT + IRV$$

Question 16

Which of the following statements about the pleura is correct?

Accepted Answer

The pleural fluid lubricates the space between the parietal and visceral pleura.

Question 17

A blood clot blocks a branch of the pulmonary artery. What is the most likely immediate effect?

Accepted Answer

Decreased blood flow to the affected lobule, causing a pulmonary embolism.

Question 18

Which of the following best explains why CO2 is transported in the blood primarily as bicarbonate ion ($$HCO_3$$^-$$)?

Accepted Answer

The conversion to bicarbonate ion allows more efficient transport and buffering of pH.

Question 19

Which of the following is a function of the respiratory defense system?

Accepted Answer

It removes particles and pathogens from inhaled air using filtration and ciliary movement.

Comprehensive Study Notes: The Respiratory System

Study Guide - Practice Questions