The nervous system

• Nervous system


  Consists of two parts: central nervous system (brain and spinal cord) and other nerves running to and from the central nervous system
• Homeostasis


  1. Stimulus

  2. Receptor

  3. Coordination Center

  4. Effector

  5. Response
• Neuron


  Nerve cell
• Reflex arc


  1. Stimulus detected by receptor

  2. Electrical impulse passed along sensory neuron to central nervous system

  3. Electrical impulse passed along relay neuron in central nervous system

  4. Electrical impulse passed along motor neuron to effector

  5. Effector (muscle) contracts, response occurs
• In reflexes, there is no decision-making by the conscious part of the brain
• Reflexes are automatic and rapid
• Reflexes help to protect us from danger