Muscle Types and Functions

Types of Muscles

• Skeletal Muscles (Voluntary Muscles):
  • Attached to bones and help move the body's skeleton
  • Under conscious control
  • Examples: biceps, quadriceps, hamstrings
• Smooth Muscles (Involuntary Muscles):
  • Found in the walls of hollow organs (e.g., digestive tract, blood vessels)
  • Not under conscious control
  • Examples: muscles in the digestive system, blood vessels
• Cardiac Muscles (Involuntary Muscles):
  • Found in the heart
  • Responsible for pumping blood throughout the body
  • Not under conscious control

Muscle Structure

• Muscle Fibers: The building blocks of muscles
• Myofibrils: Thread-like structures within muscle fibers
• Sarcomeres: Functional units of myofibrils, responsible for muscle contraction
• Actin and Myosin: Proteins that interact to produce muscle contraction

Muscle Functions

• Movement: Muscles work with bones to move the body's skeleton
• Stabilization: Muscles help maintain posture and balance
• Support: Muscles support organs and maintain internal pressure
• Protection: Muscles protect vital organs and maintain body temperature

Muscle Physiology

• Muscle Contraction: The process by which muscles generate force
  • Calcium ions (Ca2+) trigger muscle contraction
  • Actin and myosin interact to produce muscle contraction
• Muscle Relaxation: The process by which muscles return to a relaxed state
  • Calcium ions are pumped back into the sarcoplasmic reticulum
  • Actin and myosin return to their relaxed state