Muscle lab

• Functions of muscle tissue

  • Movement
  • Maintenance of Posture
  • Respiration
  • Production of body heat
  • Communication
  • Constriction of organs and vessels
  • Contraction of the heart
• Types of muscle


  • Skeletal
  • Cardiac
  • Smooth
• Skeletal muscle organization


  • Covered by thin layers of connective tissue (epimysium, perimysium, endomysium)
  • Contractile fibers are organized by the connective tissue
• Myotendinous junction


  Connection between skeletal muscle and tendon
• Skeletal muscle structure


  • Composed of sarcomeres
  • Sarcomeres contain thick (myosin) and thin (actin) filaments
• Sliding filament mechanism


  Shortening of sarcomeres due to sliding of actin and myosin filaments
• Neuromuscular junction (NMJ)


  Connection between motor neuron and skeletal muscle
• Sensory receptors associated with skeletal muscle

  • Muscle spindle
  • Tendon (Golgi) organs
• Muscle spindle


  • Stretch detectors
  • Contain intrafusal fibers
• Tendon (Golgi) organs


  • Detect changes in tension within tendons produced by muscle contractions
  • Inhibit motor nerve activity if tension is excessive
• Cardiac muscle and smooth muscle are other types of muscle tissue
• Multinucleated


  Skeletal muscle
• Mononucleated


  Smooth and cardiac muscle
• With fussiform


  Smooth muscle
• Perymisium


  the sheath of connective tissue surrounding a bundle of muscle fibers.
• Endomysium


  surrounds individual muscle fibres and contains the vessels and nerves
• Epimysium


  a sheath of fibrous elastic tissue surrounding a muscle.