Question 1

Which of the following best describes the function of Type II alveolar cells in the lungs?

Accepted Answer

They secrete surfactant to reduce surface tension and prevent alveolar collapse.

Question 2

A patient with emphysema has difficulty with gas exchange due to destruction of alveolar walls. Which factor is most directly affected?

Accepted Answer

Surface area for diffusion

Question 3

During inspiration, which of the following events occurs first?

Accepted Answer

Diaphragm contracts and moves inferiorly

Question 4

According to Boyle’s Law, what happens to the pressure in the lungs if the volume of the thoracic cavity increases, assuming temperature is constant?

Accepted Answer

Pressure decreases

Question 5

Which equation correctly represents Boyle’s Law as it applies to pulmonary ventilation?

Accepted Answer

$$P_1V_1 = P_2V_2$$

Question 6

A person is exposed to high altitude, where the partial pressure of oxygen is lower. Which process is most directly affected?

Accepted Answer

External respiration

Question 7

Which of the following best explains why surfactant is critical for normal lung function?

Accepted Answer

It decreases alveolar surface tension, preventing collapse during exhalation.

Question 8

Which of the following is the correct sequence of airflow through the respiratory tract during inhalation?

Accepted Answer

Nasal cavity → pharynx → larynx → trachea → bronchi → bronchioles → alveoli

Question 9

Which of the following best describes the Bohr effect?

Accepted Answer

Hemoglobin’s affinity for oxygen decreases as pH decreases and CO2 increases.

Question 10

A patient is experiencing hypoventilation. What is the most likely effect on blood pH and why?

Accepted Answer

Blood pH decreases due to increased CO2

Question 11

Which of the following is the primary mechanism for transporting carbon dioxide in the blood?

Accepted Answer

As bicarbonate ion in plasma

Question 12

Which equation represents the reversible reaction catalyzed by carbonic anhydrase in red blood cells?

Accepted Answer

$$CO_2 + H_2O$$ \rightleftharpoons H_2CO_3 \rightleftharpoons H^+ + $$HCO_3$$^-$$

Question 13

Which structure prevents food from entering the lower respiratory tract during swallowing?

Accepted Answer

Epiglottis

Question 14

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

Accepted Answer

It decreases airflow into the lungs.

Question 15

A person with left heart failure develops pulmonary edema. How does this affect gas exchange?

Accepted Answer

It increases the thickness of the respiratory membrane, slowing diffusion.

Question 16

Which of the following is true regarding the neural control of respiration?

Accepted Answer

The medulla generates the basic rhythm of breathing.

Question 17

Which of the following lung volumes cannot be measured directly by spirometry?

Accepted Answer

Residual volume

Question 18

Which of the following best describes the effect of sympathetic stimulation on bronchioles?

Accepted Answer

Bronchodilation via smooth muscle relaxation

Question 19

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

Accepted Answer

$$VC = TV + IRV + ERV$$

Question 20

A patient is exposed to carbon monoxide (CO), which binds to hemoglobin. What is the most likely effect on oxygen transport?

Accepted Answer

Decreased oxygen binding to hemoglobin

The Respiratory System: Structure, Function, and Physiology

Study Guide - Practice Questions