Muscle Anatomy and Function Overview

Muscle Overview

• Muscle accounts for approximately 40% of a person's weight.
• Definition: A band of fibrous tissue in the body that contracts, producing movement or maintaining position.

Muscle Tissue Structure

• Muscle tissue consists of muscle cells containing myofibrils.
• Myofibrils are contractile threads extending through muscle fibers.
• Sarcomeres are the basic structural units of muscle, composed of long fibrous proteins that slide to create dark and light bands.

Muscle Energy Source

• Muscle cells utilize Adenosine Triphosphate (ATP) as their primary energy source.
• ATP is generated through the metabolism of food into chemical energy.

Functions of Muscle

• Key functions include:
  • Maintaining posture and muscle tone
  • Facilitating digestion and circulation
  • Enabling mobility and movement
  • Regulating temperature and producing heat
  • Providing organ protection and aiding in urination and respiration

Movement Mechanics

• Lever systems coordinate bones and muscles for movement.
• Types of levers:
  • First Order Lever: Generates muscular effort to overcome loads or increases movement speed.
  • Second Order Lever: Focuses on load overcoming.
  • Third Order Lever: Enhances the speed of movements.

Heat Regulation

• Maintaining a constant body temperature is vital for healthy survival and is facilitated by muscle function.