Frog skeletal muscle fibres, coloured scanning electron micrograph (SEM). Endomysial connective tissue (yellow) containing numerous capillaries. surrounds the pink muscle fibres. Attached to the body's skeleton via flexible tendons, striated muscles are usually arranged in pairs. Each member of a pair of pulls in the direction opposite of the other one, providing precise control of the skeletal structure. Magnification: x500 when printed at 10 centimetres wide.