Muscle layers refer to the different strata of muscle tissue found in the body. These layers are primarily categorized into three types: skeletal muscle, smooth muscle, and cardiac muscle. Skeletal muscle is responsible for voluntary movements and is attached to bones, while smooth muscle controls involuntary actions in organs like the intestines and blood vessels. Cardiac muscle, found only in the heart, is specialized for continuous contraction. Each muscle layer has a unique structure and function. The skeletal muscle fibers are long and striated, allowing for quick and powerful movements. In contrast, smooth muscle fibers are shorter and non-striated, enabling slow, sustained contractions. Cardiac muscle fibers are also striated but are interconnected, allowing for synchronized heartbeats.