Muscular System

• Muscular system


  • Composed of specialized cells called muscle fibers
  • Permits movement of the body, maintains posture, and circulates blood throughout the body
• Types of muscle


  • Cardiac
  • Skeletal
  • Smooth
• Cardiac muscle

  • Involuntary muscles that contract rapidly but do not get fatigued
  • Control the contraction and relaxation of the heart
• Skeletal muscle


  • Comprise 30 to 40% of your total body mass
  • Voluntary, meaning you control how and when they work
  • Muscles that connect to your bones
  • Maintain posture and stabilize bones and joints
  • Protect the vital organs in the body
  • Control internal movement, and generate heat
• Smooth muscle


  • Involuntarily regulated, not striated, not branched, and have a single nucleus
  • Used in vessels to maintain blood pressure and flow
  • Used in the lungs to open and close airways
  • Used in the gastrointestinal system for motility and nutrition collection