CB2g-The nervous system

Cards (11)

  • List the 2 parts of the nervous system.
    CNS- Central nervous system - brain and spinal cord
    PNS- Peripheral nervous system - nerves that extend from the CNS to the rest of the body.
  • State & describe the three types of neurones
    Sensory neurones: carry impulses to the CNS
    Motor neurones: carry impulses from the CNS to effector organs
    Relay neurones: carries impulses from one part of the CNS to another
  • Describe how the nervous system detects stimuli
    • Stimuli is detected by sensory receptors
    • information is converted to a nervous (electrical) impulse
    • sent along sensory neurones to the CNS (brain, spinal cord)
    • CNS coordinates response and decides what to do about the stimulus
  • True or false: Different receptors detect different stimuli
    True!
    Examples:
    Receptors in the eye detect light
    Receptors in the skin detect pressure
  • What happens when a stimulus is detected by receptors?
    The information is converted to a nervous (electrical) impulse and sent alond sensory neurones to the CNS
  • What is reaction time?
    Time it takes you to respond to stimuli
  • Describe the structure of a sensory neurone
    -One long dendron which has dendrites at the end
    these recieve impulses from other neurones, and carries impulses to the cell body which is in the middle of the neurone
    -One short axon which is coated with a myelin sheath
    axons carry impulses away from the cell body. The myelin sheath provides electrical insulation.
  • What are the stages of response?
    StimulusReceptorSensory neuroneCNSMotor neuroneEffectorResponse
  • Describe the routes that impulses take to and from the brain
    • Sensory neurones recieve impulses and carry them from sense neurones to the brain
    • Interneurones connect sensory and motor neurones and interperet the impulse
    • Motor neurones carry impulses from the brain to muscles or glands
  • Explain how sensory neurones are adapted to their function
    The long axon and dendron of the sensory neurone means the cell can collect impulses from receptor cells and carry them through the body to the CNS

    The myelin sheath insulates the neurone from surrounding neurones and helps the electrical impulse travel faster
  • What is a stimuli?
    Something that sets off a reaction in the nervous system. Eg. heat or sound