muscles

• the 3 types of muscle tissue

  Skeltal; cardiac; smooth muscle
• Functions of skeletal muscles 


  Produce skeltal movement; Maintain posture; support soft tissue; maintian body temp;store nutrients
• organisation of muscle at tissue level 


  epimysium; perimysium; endomysium
• skeletal muscle fibre layers

  myofibrols; myofilament and sarcomeres
• structure of sarcomeres 


  A band; I band and thick filaments
• sarcomeres structure (photo)

  
• musclur impulses

  • Site of action is the neuromuscular junction

  1. Axon contains neurotransmitter (Ach)
  2. Action potential travels along axon
  3. Triggers release when reaches terminal
  4. ACh diffuses across synaptic cleft
  5. Na+ inrush triggers muscle action potential
• anatomical arrangment of fascicles

  Parrallel, convergent, pennate, circular
• parrallel muscle types


  Fibres parrallel to long axis of muscle and have tendons on each end (biceps)
• convergent muscle 


  Fan shaped and braod attatchemnt at other end (pecs)
• pennate muscles


  Form a common angle with tendon and generate less movement but more force (deltoids)
• circular muscles 


  sphincter muscle (closes mouth)
• class of levers 


  1st, 2nd (force), 3rd (speed)
• muscle actions


  agonist (prime mover) antagonist (opposes prime mover) synergist (assists prime mover) fixator (stabilse)
• Shape and size of muscles (naming)

  • long muscles are called longus