New York State Basic Emergency Medical Technician (EMT-B) Practice Exam

Which of the following is NOT part of the respiratory system?

1. Trachea

2. Alveoli

3. Bronchi

4. Esophagus

The correct answer is: Esophagus

The esophagus is indeed not part of the respiratory system; rather, it is a component of the digestive system. Its primary function is to transport food from the throat to the stomach, whereas the respiratory system is responsible for the exchange of gases—specifically oxygen and carbon dioxide—during the process of breathing. The trachea, bronchi, and alveoli are all essential structures within the respiratory system. The trachea serves as the main airway that directs air into the lungs. The bronchi are the passages that branch from the trachea into the lungs, further dividing into smaller tubes. Alveoli are tiny air sacs within the lungs where gas exchange occurs, allowing oxygen to enter the bloodstream and carbon dioxide to be expelled. Understanding these distinctions is crucial for recognizing how the body functions in terms of both respiration and digestion.