Emergency Medical Technician (EMT) Intermediate Practice Exam

What is tidal volume?

1. The volume of air reserved for deep breaths

2. The volume of air moved into or out of the lungs during a single breath

3. The total volume of air in the lungs

4. The volume of air expelled forcefully

The correct answer is: The volume of air moved into or out of the lungs during a single breath

Tidal volume refers to the volume of air that is inhaled or exhaled during a single breath under resting conditions. It is a crucial measurement in understanding respiratory function, particularly in assessing how effectively a person's lungs are exchanging gases. In a typical adult, tidal volume is around 500 milliliters per breath, but this can vary based on individual factors such as body size, age, and physical conditioning. The other options define different aspects of lung mechanics or respiratory volumes. For instance, the air reserved for deep breaths pertains to inspiratory reserve volume, while the total volume of air in the lungs refers to total lung capacity, which includes several other measurements. The volume expelled forcefully relates to expiratory reserve volume or forced expiratory volume, which accounts for the air that can be forcibly exhaled after a normal exhalation. Understanding tidal volume is essential for EMTs, as it helps assess and manage patients with respiratory conditions.