Q: If a person’s tidal volume is 500 ml, respiratory rate is 12 breaths/min, and anatomical dead space is 150 ml, what is their alveolar ventilation rate (AVR)?

$$AVR = 12 \times (500 - 150) = 4,200\ \text{ml/min}$$

Question 1

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

Accepted Answer

It reduces the surface tension of alveolar fluid, preventing alveolar collapse.

Question 2

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

Accepted Answer

Impaired gas exchange leading to hypoxemia.

Question 3

According to Boyle’s Law, if the volume of the thoracic cavity increases during inspiration, what happens to the intrapulmonary pressure?

Accepted Answer

It decreases below atmospheric pressure.

Question 4

Which equation correctly represents the relationship described by Boyle’s Law?

Accepted Answer

$$P_1V_1 = P_2V_2$$

Question 5

A scuba diver ascends rapidly from deep water, causing nitrogen to come out of solution in the blood. Which gas law best explains this phenomenon?

Accepted Answer

Henry’s Law

Question 6

Which of the following changes would most likely shift the oxygen-hemoglobin dissociation curve to the right, enhancing oxygen unloading at the tissues?

Accepted Answer

Increased 2,3-BPG concentration

Question 7

A patient with chronic bronchitis has increased airway resistance. Which of the following best explains why breathing becomes more difficult?

Accepted Answer

Airway resistance is inversely proportional to airflow, so increased resistance decreases airflow.

Question 8

Which of the following is the main form in which carbon dioxide is transported in the blood?

Accepted Answer

As bicarbonate ion in plasma

Question 9

If a person’s tidal volume is 500 ml, respiratory rate is 12 breaths/min, and anatomical dead space is 150 ml, what is their alveolar ventilation rate (AVR)?

Accepted Answer

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

Question 10

Which structure acts as a switching mechanism to route air and food into the proper channels and is also involved in voice production?

Accepted Answer

Larynx

Question 11

A patient with a spinal cord injury at the level of the cervical vertebrae may have difficulty breathing primarily because:

Accepted Answer

The diaphragm is innervated by the phrenic nerve, which arises from the cervical spinal cord.

Question 12

Which of the following best describes the Haldane effect?

Accepted Answer

The lower the PO2 and hemoglobin saturation with oxygen, the more carbon dioxide can be carried in the blood.

Question 13

Which of the following is NOT a factor that would diminish lung compliance?

Accepted Answer

Increased production of surfactant

Question 14

During vigorous exercise, which of the following statements is TRUE regarding arterial PO2 and PCO2 levels?

Accepted Answer

Arterial PO2 and PCO2 levels remain fairly constant.

Question 15

Which of the following best explains why a person with emphysema has decreased surface area for gas exchange?

Accepted Answer

Destruction of alveolar walls

Question 16

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

Accepted Answer

$$VC = TV + IRV + ERV$$

Question 17

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

Accepted Answer

Blood pH will decrease, leading to acidosis.

Question 18

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

Accepted Answer

They help humidify and filter inspired air.

Question 19

Which of the following best describes the Bohr effect?

Accepted Answer

A decrease in pH weakens the hemoglobin-oxygen bond, enhancing oxygen unloading.

Question 20

Which of the following is the correct sequence of airflow during inspiration?

Accepted Answer

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

The Respiratory System: Structure, Function, and Physiology

Study Guide - Practice Questions

Study Guide - Flashcards