What does the respiratory system consist of?

The respiratory system is primarily responsible for the exchange of gases — oxygen and carbon dioxide — between the air and the bloodstream. It is comprised of various structures that facilitate this vital function. The correct answer identifies the upper and lower airways, which include the nasal passages, pharynx, larynx, trachea, bronchi, and lungs, as well as their component parts. This comprehensive structure allows air to be inhaled, processed, and exhaled efficiently.

Understanding the various components is essential because each part plays a specific role in respiration. The upper airways filter, warm, and humidify the incoming air, while the lower airways and lungs are where gas exchange actually occurs.

Other options do not capture the full complexity of the respiratory system. For example, stating that it consists only of the lungs ignores the critical role of airways in delivering air to the lungs. Similarly, including the heart, while important in cardiovascular function, does not pertain to the anatomy and function of the respiratory system itself, which is focused solely on breathing and gas exchange. Finally, while the diaphragm and thoracic cavity are important for the mechanics of breathing, they do not encompass all parts of the respiratory system as a whole.