Which root specifically identifies with 'arm' in medical terminology?

The root that specifically identifies with 'arm' in medical terminology is brachi/o. This term is derived from the Latin word "bracchium," which means arm. In medical terminology, it is often used in various terms related to the arm, such as brachial, which pertains to the arm or to the major artery that supplies blood to the arm.

Other choices include roots that relate to different body parts or systems. For instance, bronchiol/o refers to the bronchioles found in the respiratory system; blephar/o relates to the eyelids; and calc/o is associated with calcium or calcification processes in bones. Each of these roots serves a unique purpose in medical terminology, thus highlighting why brachi/o is distinctly identified with the arm. Understanding these root words is essential for comprehending and constructing medical terms accurately.