NBRC Cardiopulmonary Anatomy and Physiology

Question 1

Which of the following best describes the primary function of the alveoli?

Accepted Answer

Gas exchange between air and blood

Answer

Alveoli are the primary sites of gas exchange where oxygen diffuses into the blood and carbon dioxide diffuses out.

Question 2

The normal partial pressure of oxygen (PaO2) in arterial blood at sea level is approximately:

Accepted Answer

80–100 mmHg

Answer

Normal PaO2 ranges from 80 to 100 mmHg in a healthy adult breathing room air at sea level.

Question 3

Which muscle is the primary muscle of inspiration?

Accepted Answer

Diaphragm

Answer

The diaphragm contracts and flattens during inspiration, generating the pressure gradient that draws air into the lungs.

Question 4

What is the Bohr effect?

Accepted Answer

Increased CO2 shifts the oxyhemoglobin curve right

Answer

The Bohr effect describes how elevated CO2 (and decreased pH) reduces hemoglobin's affinity for oxygen, shifting the oxyhemoglobin dissociation curve to the right.

Question 5

Which lung zone, according to the West zones model, has the greatest blood flow?

Accepted Answer

Zone 3 (base)

Answer

Zone 3 (base) has the greatest blood flow because both arterial and venous pressures exceed alveolar pressure, keeping pulmonary capillaries continuously open.

NBRC - National Board for Respiratory Care Practice Test

NBRC - National Board for Respiratory Care Practice Test

NBRC Cardiopulmonary Anatomy and Physiology