What term describes the space in the respiratory system that does not facilitate gas exchange?

• A. Functional residual capacity
• B. Dead air space
• C. Alveolar space
• D. Respiratory reserve volume

Answer: (B)

The term that describes the space in the respiratory system that does not facilitate gas exchange is known as dead air space. This refers to areas within the respiratory system where air is present but does not participate in the exchange of oxygen and carbon dioxide.

Dead air space includes parts of the respiratory tract such as the trachea, bronchi, and bronchioles, where air can be inhaled but is not reaching the alveoli, the primary site where gas exchange occurs. The presence of dead air space can influence the efficiency of ventilation, as it dilutes fresh air reaching the alveoli and reduces the overall effectiveness of oxygen uptake and carbon dioxide removal.

Other terms listed, such as functional residual capacity and respiratory reserve volume, refer to lung volumes related to overall lung capacity and respiratory function, but they do not specifically denote regions devoid of gas exchange. Alveolar space, on the other hand, is where gas exchange actually takes place within the alveoli, thus further distinguishing dead air space as a non-participating area in this critical process.