muscle tissue 1

• muscles are composed of cells that are elongated and form fibres
• muscle cells contain protein filaments called actin and myosin that enable muscles to contract and cause movement
• skeletal muscle

  found attached to bones, can control its contraction and relaxation, sometimes contracts in response to reflexes
• cardiac muscle

  found only in heart. contracts at steady rate to make heartbeat, not under voluntary control
• smooth muscle

  found in walls of hollow organs, such as stomach and bladder, not under voluntary control
• skeletal muscle fibre

  muscle tissue needs to be able to contract (shorten in length) in order to move bones
• skeletal muscle fibre

  in muscle, cells join up to make muscle fibres, long strands of cells sharing nuclei and cytoplasm, known as sarcoplasm
• skeletal muscle fibre

  inside muscle cell cytoplasm are many mitochondria, specialised endoplasmic reticulum known as sarcoplasmic reticulum and number of microfibrils
• skeletal muscle fibre

  each muscle fibre surrounded by cell surface called sarcolemma
• skeletal muscle fibre

  shows a stripy/banding appearance under microscope
• skeletal muscle fibre

  made up of thousands of muscle fibre, each muscle fibre made up of myofibrils