The Nervous System

• Central Nervous System (CNS)


  the command center (brain/spinal cord); processing information, coordinating responses, regulating body functions
• Peripheral Nervous System (PNS)


  all nerves and ganglia aside from brain/spinal cord; a communication network
• Autonomic Nervous System

  regulates involuntary bodily functions
• Sympathetic Nervous System

  activates fight or flight response
• Parasympathetic Nervous System

  promotes relaxation and restoration of a calm state
• Somatic Nervous System

  controls voluntary movements and relays information from the body to the brain
• Glial Cells


  support cells
• Motor Neurons


  transmit signals from our brains to our glands
• Sensory Neurons


  transmit sensory information from sensory receptors
• Interneurons


  connectors within the nervous system and relays signals between sensory and motor neurons
• All-or-Nothing Principle


  if the stimulus is strong enough, there will be a full-strength response; if it is weak, there will not be a response at all
• Multiple Sclerosis


  an autoimmune disease that affects the central nervous system
• Myasthenia Gravis

  an autoimmune disorder that affects the neuromuscular junction