ï»¿ Microscopic Appearance of Skeletal Muscle Let's examine the microscopic appearance of skeletal muscle. Skeletal muscle is responsible for voluntary movements, such as walking and playing sports. Hundreds of skeletal muscles attach to the skeleton, giving us the ability to perform precise movements. Skeletal muscle cells have a long fibrous appearance that is visible, even at a low magnification. This fibrous appearance is why muscle cells are also called muscle fibers. Each muscle fiber has multiple nuclei on the outer periphery of the cell. Here is a cross section of muscle fibers. Myofibrils fill much of the interior space of skeletal muscle fibers. At a high magnification, the banding pattern becomes apparent on oil immersion, the dark A bands... ...and the light I bands, can be observed. This striped appearance is known as striation. Notice the Z lines are visible within the I bands in this specimen. Let's finish by examining the microscopic appearance of skeletal muscle. Muscle fibers. Nuclei. Myofibrils. A bands. I bands. Z lines.