What is the root word for muscle?

The root word for muscle is indeed "my/o." This term is derived from the Greek word "mys," meaning muscle. It is commonly used in medical terminology to form words related to muscles, such as "myopathy," which refers to a disease of the muscle tissue. Understanding root words like "my/o" is crucial in medical contexts, as they serve as building blocks for forming terms that describe various conditions, anatomical structures, or processes related to muscles.

The other root words listed pertain to different anatomical structures or conditions. For instance, "lord/o" relates to the curvature of the spine, "spondyl/o" refers specifically to vertebrae and the spine, and "por/o" is associated with pores or openings in tissues. None of these options pertain to muscle, distinguishing "my/o" as the correct choice.