skeletal muscles come in different shapes and sizes but the main structure of a skeletal muscle cell is basically the same if we were to take a cross section of a single muscle we would find it is covered in a protective sheath or layer called the epimysium the epimysium protects the muscle from friction against other muscles and Bones it also continues at the end of the muscle to form along with other connective tissues the tendon which attaches the muscle to the Bone each muscle is made up of a number of bundles of muscle fibers called fasciculi the fasciculiae are contained within another connective tissue called the paramecium each bundle of muscle fibers contains anywhere from 10 and 100 individual fibers a large strong muscle such as those in the quadriceps group would have a large number of fibers within each bundle a smaller muscle used for precision movement such as those in the hand would contain far fewer muscle fibers in each bundle each muscle fiber is also covered in a fibrous connective layer of tissues called the endomysium which insulates each fiber beneath the endomysium is the sarcolemma which is the muscle fiber cell membrane and beneath this is the sarcoplasm this is a gelatinous fluid which contains glycogen and fats for energy as well as mitochondria inside which the cell's energy is produced each muscle fiber itself contains cylindrical organelles known as myofibrils each muscle fiber contains hundreds or thousands of myofibrils which themselves are bundles of proteins called actin and myosin these run the length of the muscle fiber and are important in muscle contraction surrounding the myofibril there is a network of tubules and channels called the sarcoplasmic reticulum where calcium is stored which is also important for muscle contraction each myofibril can be broken down into functional repeating segments called sarcomeres which are the basis for muscle contraction Theory known as sliding filament theory for more on physical education and sports coaching don't forget to click like And subscribe