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
• Nervous system


  • Enables humans to react to their surroundings and coordinate their behavior
• Reflex arc


  1. Stimulus detected by receptor

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

  3. Electrical impulse passed from relay neuron to motor neuron

  4. Electrical impulse passed down motor neuron to effector (muscle)

  5. Muscle contracts, response (e.g. pulling hand away from heat)
• Reflexes are automatic and rapid, with no decision-making by the conscious part of the brain
• Reflexes help to protect us from danger