Contraction cycle

Cards (6)

  • Neuron signals (nerve impulses)
    1. Released from the spinal cord
    2. Release of calcium
    3. Synaptic pump releases acetylcholine
  • Muscle contraction
    1. Acetylcholine attaches to acetylcholine receptors in muscle fibers
    2. Muscle is in an excitation state
  • Cross-bridge cycle

    Connection between the head of myosin filaments and actin filaments causes action
  • ATP hydrolysis
    1. ATP hydrolyses to ADP and phosphate
    2. Myosin is ready to attach to actin filaments
  • Calcium attachment
    1. Calcium attaches to troponins
    2. Exposes the site of attachment in actin filaments
    3. Power stroke state where the sarcomere shortens
  • Muscle contraction and relaxation
    1. ATP plays an important role in the separation of the myosin and actin
    2. When the muscle is in a resting position, tropomyosin and troponin block the myosin-binding sites on actin filaments