nervous system + responding to stimuli

• what is a receptor?

  • group of cells which detect external stimuli
• what are effectors?

  • cells that bring a response to stimuli
• how do receptors and effectors communicate with one another?

  • either hormonal or nervous system or sometimes both
• what is the CNS?

  • consist of brain and spinal cord
  • when receptors in sense organ detect a stimulus - send electrical impulses along sensory neurone to CNS
  • CNS sends electrical impulses to effector along motor neurone - effector responds
  • neurons transmit high speed electrical impulses = very rapid responses
• what is a synapse?

  • connection between two neurons
  • nerve signal transferred by neurotransmitters - diffuse across gap
  • these chemicals set off new electrical signal in the next neuron