Question 1

Which of the following best describes the primary function of the respiratory mucosa in the conducting portion of the respiratory system?

Accepted Answer

It traps and removes particles and pathogens from inhaled air through mucus and ciliary action.

Question 2

During an asthma attack, which physiological change occurs in the bronchioles?

Accepted Answer

Bronchioles constrict due to excessive stimulation of smooth muscle, increasing airway resistance.

Question 3

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

Accepted Answer

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

Question 4

A patient with pneumonia has fluid accumulation in the alveoli. How does this affect gas exchange?

Accepted Answer

It increases the diffusion distance, compromising the efficiency of the blood air barrier.

Question 5

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 6

Which of the following is a direct result of surfactant deficiency in premature infants?

Accepted Answer

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

Question 7

A pulmonary embolism blocks a branch of the pulmonary artery. What is the most immediate consequence?

Accepted Answer

Decreased blood flow to a region of the lung, reducing gas exchange in that area.

Question 8

Which of the following statements about the pleura is correct?

Accepted Answer

Pleural fluid lubricates the space between the parietal and visceral pleura, reducing friction during breathing.

Question 9

Which muscles are primarily responsible for normal, quiet inhalation?

Accepted Answer

Diaphragm and external intercostal muscles

Question 10

Which of the following best describes the oxygen–hemoglobin saturation curve when blood pH decreases or temperature increases?

Accepted Answer

The curve shifts to the right, and hemoglobin releases oxygen more easily.

Question 11

A person is exposed to carbon monoxide (CO). What is the physiological consequence at the level of hemoglobin?

Accepted Answer

CO binds strongly to hemoglobin, displacing O2 and reducing oxygen transport.

Question 12

According to Henry’s Law, what happens when the partial pressure of a gas above a liquid increases?

Accepted Answer

The amount of gas dissolved in the liquid increases.

Question 13

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

Accepted Answer

$$VC = ERV + VT + IRV$$

Question 14

Which of the following best explains why CO2 diffuses more rapidly than O2 across the blood air barrier, despite a smaller partial pressure gradient?

Accepted Answer

CO2 is more soluble in plasma than O2.

Question 15

Which of the following is a direct effect of hypercapnia (elevated arterial PCO2) on the respiratory system?

Accepted Answer

Increased respiratory rate and depth to eliminate excess CO2.

Question 16

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

Accepted Answer

It functions in quiet and forced breathing by stimulating inspiratory muscles.

Question 17

Which of the following age-related changes most directly reduces vital capacity in the elderly?

Accepted Answer

Deterioration of elastic tissue in the lungs

Question 18

Which of the following is the main reason why only a portion of inhaled air reaches the alveoli for gas exchange?

Accepted Answer

Some air remains in the anatomic dead space of the conducting passages.

Question 19

Which of the following best describes the effect of a pneumothorax on lung function?

Accepted Answer

It increases intrapleural pressure, causing lung collapse (atelectasis).

The Respiratory System: Structure, Function, and Regulation

Study Guide - Practice Questions