What is muscle? How to use in English

The word "muscle" originates from the Latin word "musculus," which means "little mouse." This may seem unusual, but it's due to the ancient Greeks and Romans' observation of the movement of mice when they were exposed to heat. They noticed that mice's legs would contract and relax, much like human muscles, as they moved. As a result, the Greek physician Galen (129-216 AD) referred to the striated muscles of the human body as "muskoi" or "little mice," which the Latin language later adopted as "musculus." The term eventually evolved into the English word "muscle," describing the fibers responsible for movement, strength, and contraction in the human body.