What root word is commonly associated with the term "muscle"?

The root word that is commonly associated with the term "muscle" is indeed "my/o." This Greek-derived term specifically pertains to muscle tissue and is often used in medical terminology to form words related to muscular conditions, anatomy, and physiology. For example, words like "myopathy" (a disease of muscle tissue) and "myalgia" (muscle pain) incorporate this root. Understanding the root "my/o" helps in recognizing and interpreting various medical terms related to muscles, which is essential for diagnosing and discussing muscle-related health issues.

The other root words, while relevant to different areas of medicine, do not pertain to muscle. "Por/o" relates to pores or openings, often used in contexts like "porous," "sarc/o" signifies flesh or connective tissue, and "lith/o" pertains to stones or calculi in the body. Thus, "my/o" is distinctly focused on muscles, making it the correct answer.