The reflex arc - sensory,relay,motor -neuron

• What type of cells are responsible for quick reactions to pain?

  Neurons
• What is the structure formed by neurons that allows for quick reactions called?

  A reflex arc
• What are the three types of neurons involved in a reflex arc?

  • Sensory neuron
  • Relay neuron
  • Motor neuron
• What color represents the sensory neuron in the diagram?

  Blue
• What color represents the relay neuron in the diagram?

  Purple
• What color represents the motor neuron in the diagram?

  Green
• What does the cell body of a neuron contain?

  The nucleus of the cell
• What are the two main structures on the length of a neuron?

  Axon and dendrites
• What is the function of axon terminals?

  They transmit signals to the next neuron
• What is the synapse?

  The junction where axon terminals almost touch the dendrites of the next neuron
• What is the myelin sheath made of?

  Schwann cells
• What is the role of the myelin sheath?

  It protects the cell and increases the speed of transmission
• What is the muscle at the end of the motor neuron called?

  The effector
• What are the steps involved in the reflex arc process?

  1. Sensation detected by sensory receptors
  2. Electrical signal travels along dendrite to axon
  3. Signal converts to chemical at axon terminal
  4. Chemical crosses synapse to relay neuron
  5. Reflex response sent to motor neuron
  6. Information sent to the central nervous system
• What happens when the signal reaches the motor neuron?

  It activates the effector, causing movement
• What is the fastest type of neuron in the body?

  The alpha motor neuron
• How fast can the alpha motor neuron transmit information?

  At 119 meters per second
• What is proprioception?

  The sense of where our body is in space
• What is the speed of type C neurons that transmit pain?

  One mile per hour
• Why do type C neurons transmit pain signals slowly?

  They are often smaller and unmyelinated
• What resources are available for further study on psychology?

  • Over 140 videos on psychology
  • A website full of resources
  • Options to share with teachers or study groups