Muscular System

• Muscular - responsible for the movement of the body and maintaining posture.
• Types of muscles

  • Skeletal muscle - attached to bones
  • Cardiac muscle - walls of the heart
  • Smooth muscle - walls of internal organs (e.g. small intestine, stomach, blood vessels)
• Skeletal muscles

  • These cells are multinucleated and have a striated appearance due to the arrangement of actin and myosin filaments within the cell.
  • They are responsible for voluntary movements such as walking, jumping, and lifting weights.

  
• Smooth muscles

  • Smooth muscle cells are spindle-shaped and have a single nucleus.
  • They are responsible for involuntary movements such as the contraction of the stomach during digestion or the constriction of blood vessels in response to stress or injury.

  
• Cardiac muscles

  • These cells are also striated, branched and have a single nucleus.
  • Responsible for the rhythmic contraction of the heart that pumps blood throughout the body.