Muscle

• Muscle Cells – body movement
• A muscle cells consists of three main parts:

  • Nuclei - attached to bones and is responsible for voluntary movements such as walking.
  • Cytoplasm – muscle cells is packed with contractile proteins
• KEY NOTES

  • Energy production: Muscle cells generate ATP, the energy needed for contraction, through aerobic respiration, anaerobic respiration, and creatine phosphate metabolism.
  • Plasticity: Muscle cells can adapt and change in response to exercise or injury, increasing in size and strength with resistance training.
• There are three main types of muscles:

  • Skeletal muscle - attached to bones and is responsible for voluntary movements such as walking.
  • Cardiac muscle – found in the heart and is responsible for generating the force that pumps blood.
  • Smooth muscle - found in the walls of organs and blood vessels and is responsible for involuntary movements such as peristalsis.

  
• KEY NOTES

  • Sarcomere: The basic unit of muscle contraction, composed of overlapping actin and myosin filaments that slide past each other to generate force.
  • Neuromuscular junction: The point where a motor neuron meets a muscle cell, where neurotransmitters released by the motor neuron stimulate the muscle cell to contract.

  
• Muscle Cells