Nervous pathway

• stimulus 


  change in the environment - external or internal
• info gets received as a receptor and is sent as an electrical impulse along a sensory neuron towards the central nervous system (cns)
• cns is comprised of the brain and spinal cord
• the cns is where the impulse is passed through relay neurons and a response to the stimulus is coordinated (consciously or subconsciously)
• the cns sends info about the response along motor neurons as electrical impulses
• the effectors receive the impulse and carry out the response
• stimulus -> receptor -> sensory neuron -> relay neuron (CNS) -> motor neuron -> effector -> response
• examples of receptors 


  cells in skin responding to pressure or temp changes
• examples of effectors


  muscles contracting for movement
• the nervous system allows a fast, short-lived response to a stimulus
• axon


  main part of a nerve cell, long stretched out fibre of cytoplasm the electrical impulses travel along
• myelin sheath


  a layer of fatty cells some axons are surrounded with to insulate the electrical impulse
• dendrites


  the branched endings that connect neurons together creating a network