Nerve impulses

• What are the two main components of the nervous system?

  Peripheral nervous system and central nervous system
• What does the central nervous system consist of?

  Brain and spinal cord
• What is a neuron?

  A nerve cell that carries signals
• What do neurons carry?

  Electrical signals or nerve impulses
• What is the function of dendrites in a neuron?

  They receive chemical signals
• What is the myelin sheath?

  Insulation around the axon
• What are Schwann cells?

  Cells that form the myelin sheath
• What are the gaps between Schwann cells called?

  Nodes of Ranvier
• What is the difference between myelinated and non-myelinated neurons?

  Myelinated neurons have a myelin sheath
• How does the diameter of myelinated neurons compare to non-myelinated neurons?

  Myelinated neurons have a larger diameter
• What color are myelinated neurons typically?

  White
• What type of signals do non-myelinated neurons carry?

  Slow impulses for aches and soreness
• What type of signals do myelinated neurons carry?

  Quick signals for sharp pain
• What are the three types of neurons?

  Sensory, motor, and relay neurons
• What do sensory neurons do?

  Carry signals from receptors to the CNS
• What is the function of motor neurons?

  Carry signals to effectors like muscles
• Where are relay neurons found?

  In the central nervous system
• How do motor neurons differ from sensory neurons?

  Motor neurons send signals to muscles
• What are the differences between myelinated and non-myelinated neurons?

  • Myelinated neurons have a myelin sheath
  • Non-myelinated neurons lack a myelin sheath
  • Myelinated neurons have a larger diameter
  • Non-myelinated neurons have a smaller diameter
  • Myelinated neurons are white; non-myelinated are gray
  • Myelinated neurons transmit impulses quickly; non-myelinated transmit slowly
• What are the functions of the three types of neurons?

  • Sensory neurons: Carry signals from receptors to CNS
  • Motor neurons: Carry signals from CNS to effectors
  • Relay neurons: Connect sensory and motor neurons in CNS