Question 1

Which of the following best describes the relationship between pressure and volume in the lungs during pulmonary ventilation, according to Boyle's Law?

Accepted Answer

Pressure and volume are inversely proportional; as volume increases, pressure decreases.

Question 2

A patient suffers a stab wound that punctures the parietal pleura. Which of the following is the most likely immediate consequence?

Accepted Answer

Intrapleural pressure will equalize with atmospheric pressure, leading to lung collapse (pneumothorax).

Question 3

Which equation correctly represents the mathematical relationship for lung compliance ($$C_L$$)?

Accepted Answer

$$C_L = \frac{\Delta V}{\Delta (P_{pul} - P_{ip})}$$

Question 4

During a severe asthma attack, airway resistance increases dramatically. According to the equation $$F = \frac{\Delta P}{R}$$, what must happen to maintain normal airflow ($$F$$)?

Accepted Answer

Increase the pressure gradient ($$\Delta P) to $$compensate for increased resistance ($$R).$$

Question 5

A premature infant is diagnosed with infant respiratory distress syndrome (IRDS). Which of the following best explains the underlying cause?

Accepted Answer

Insufficient surfactant increases alveolar surface tension, causing alveoli to collapse after each breath.

Question 6

Which of the following scenarios would most likely decrease lung compliance?

Accepted Answer

Development of pulmonary fibrosis, replacing lung tissue with nonelastic scar tissue.

Question 7

A patient is breathing rapidly and shallowly. How does this affect their alveolar ventilation rate (AVR), and why?

Accepted Answer

AVR decreases because a greater proportion of each breath is dead space, reducing effective gas exchange.

Question 8

Which of the following best describes the effect of surfactant on alveolar surface tension?

Accepted Answer

Surfactant decreases surface tension, preventing alveolar collapse.

Question 9

A patient with emphysema has a reduced alveolar surface area. What is the most direct consequence for external respiration?

Accepted Answer

Decreased efficiency of gas exchange due to less surface area for diffusion.

Question 10

Which of the following is true regarding the partial pressures of oxygen ($$P_{O_2$}) in $$the alveoli and pulmonary capillaries during external respiration?

Accepted Answer

Alveolar $$P_{O_2$} is $$higher than venous blood $$P_{O_2$}$$, so oxygen diffuses into the blood.

Question 11

Which of the following best explains why a person with a blocked bronchiole (atelectasis) may experience reduced oxygenation of blood?

Accepted Answer

Blocked bronchioles prevent air from reaching some alveoli, reducing the surface area available for gas exchange.

Question 12

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

Accepted Answer

$$V_E = 	ext{tidal volume} 	imes 	ext{respiratory rate}$$

Question 13

A patient has a tidal volume of 500 mL, a respiratory rate of 12 breaths/min, and an anatomical dead space of 150 mL. What is their alveolar ventilation rate (AVR)?

Accepted Answer

$$AVR = (500 	ext{ mL} - 150 	ext{ mL}) 	imes 12 = 4,200 	ext{ mL/min}$$

Question 14

Which of the following best describes the effect of increased thickness of the respiratory membrane on gas exchange?

Accepted Answer

It decreases the rate of diffusion of gases.

Question 15

Which of the following is a normal value for atmospheric pressure ($$P_{atm}) at $$sea level?

Accepted Answer

$$P_{atm} = 760 	ext{ mm Hg}$$

Question 16

Which of the following best explains why epinephrine is used during an acute asthma attack?

Accepted Answer

Epinephrine dilates bronchioles, reducing airway resistance and improving airflow.

Question 17

Which of the following is the primary determinant of the direction of gas movement during external respiration?

Accepted Answer

The partial pressure gradients of individual gases.

Question 18

A patient with restrictive lung disease has a reduced vital capacity (VC). Which of the following best explains this finding?

Accepted Answer

Decreased lung compliance limits the expansion of the lungs, reducing the maximum volume of air that can be exhaled after a maximal inspiration.

Question 19

Which of the following best describes the effect of water's high surface tension in the alveoli?

Accepted Answer

It tends to cause alveoli to shrink to their smallest size, promoting collapse.

Respiratory Physiology: Mechanics of Breathing and Pulmonary Ventilation

Study Guide - Practice Questions

Study Guide - Flashcards