Muscles structure

Each muscle fibre is actually a giant muscle cell. •Each muscle fibre is cylindrical in shape. •Muscle fibres are surrounded by a membrane called a sarcolemma. •The sarcoplasm (cytoplasm) contains many nuclei and mitochondria. •Muscle fibres also contain sarcoplasmic reticulum which is a store of calcium ions •Each muscle fibre contains many smaller muscle fibres called MYOFIBRILS. •Myofibrils are made up of sections called sarcomeres. •Each sarcomere is made up of many proteins (called actin and myosin).