Which of the following roots is used to describe a small airway in the lungs?

The correct root to describe a small airway in the lungs is "bronchiol/o." This root specifically refers to bronchioles, which are the smaller branches of the bronchial tree that lead to the alveoli, where gas exchange occurs. Understanding this term is essential in the context of respiratory anatomy and physiology.

The other roots listed have different meanings and are unrelated to the respiratory system. For example, "bronch/o" refers to the larger bronchial tubes that branch off from the trachea and lead into the lungs, but it does not denote the smaller airways.

"Calc/o" pertains to calcium and is often used in terms related to relating to bone density or mineralization.

"Burs/o" refers to bursae, which are small fluid-filled sacs that help reduce friction in joints.

Recognizing these distinctions is important as it allows for accurate communication regarding different structures and functions within the body, particularly in a medical context.