Muscular System

• Muscular system


  An organ system that permits movement of the body, maintains posture, and circulates blood throughout the body
• Muscular system


  • Together with the skeletal system it forms the musculoskeletal system, which is responsible for movement of the human body
• Functions of the muscular system


  • Enable the body to move
  • Produce heat in the body
  • Pump the blood
  • Formed by other internal organ
  • Maintain the posture of the body
• Properties of the muscle

  • Excitable / Irritable - receiving and responding
  • Contractible - contracting
  • Extensible - stretched
  • Elasticity - return to it's original shape
  • Adaptability - can be changed
• Movements of the muscle

  • Adduction - moving a body part toward the mid-line of the body
  • Abduction - moving a body part away from the body
  • Flexion - bending a joint to decrease the angle between two bones or two body parts
  • Extension - straightening and extending of the joint to increase the angle between two bones or body parts
  • Rotation - involves moving body part around an axis
  • Circumduction - it is a combination
• Kinds of muscles


  • Smooth muscles (visceral) - Formed by internal organ, Involuntary (action cannot be controlled), Non striated (cannot stretch)
  • Cardiac muscles - Muscles in the heart, Involuntary (action cannot be controlled), Striated (can stretch)
  • Skeletal muscles - Attached to the muscles, Voluntary (controlled by will), Striated (can stretch)
• Skeletal muscle


  • Each skeletal muscle has a muscle fiber which is a single cylindrical muscle cell. An individual skeletal muscle may be made up of hundreds, or even thousands, of muscle fibers bundled together and wrapped in a connective tissue covering. Each bundle of muscle fiber is called a fasciculus.
• Connective tissue of muscle

  • Endomysium - surrounded connective tissue of muscle fiber
  • Perimysium - surrounded connective tissue of fasciculus
  • Epimysium - surrounded connective tissue of a muscle
  • Fascia - connective tissue outside the epimysium that separated the different muscles outside the bundle