Anatomy and Physiology II Practice Test

Which of the following is NOT classified as a respiratory organ?

1. nose

2. esophagus

3. trachea

4. larynx

The correct answer is: esophagus

The esophagus is primarily a component of the digestive system, responsible for transporting food and liquids from the mouth to the stomach. Unlike the other listed structures which are integral to the process of respiration, the esophagus does not facilitate gas exchange or play a direct role in breathing. In contrast, the nose is involved in filtering, warming, and humidifying inhaled air; the trachea serves as a major airway, connecting the larynx to the bronchi, allowing air passage to the lungs; while the larynx, often referred to as the voice box, is essential for phonation and also plays a role in regulating airflow into the trachea and lungs. Hence, the esophagus stands out as not being a respiratory organ.