Which of the following is NOT a non-respiratory air movement?

The correct answer is that breathing is not classified as a non-respiratory air movement. Breathing, or ventilation, is the process of moving air in and out of the lungs, which is essential for gas exchange—the primary function of the respiratory system. It includes both inhalation and exhalation phases, during which oxygen is brought into the body and carbon dioxide is expelled.

In contrast, yawning, sneezing, and coughing are classified as non-respiratory air movements because they serve different physiological functions rather than participating directly in the exchange of gases. Yawning is often associated with boredom or fatigue and helps increase oxygen intake. Sneezing is a reflex to clear irritants from the nasal passages, while coughing serves to clear the airways of mucus or foreign particles. Each of these movements involves the rapid expulsion of air and is triggered by specific stimuli, rather than being a part of the regular respiratory cycle.