Neurones

Cards (24)

  • Nerve endings allow connections
  • Axon is an extension of the cytoplasm, that carries nerve impulses away from the cell body
  • Nerve endings are between neurons or to receptors
  • Parts of a neurone
    • Cell body
    • Dendrite
    • Axon
    • Myelin sheath
    • Nucleus
  • Sensory neurone
    Transmits impulses from the receptors to the Central Nervous System (CNS)
  • Motor neurone
    Transmits impulses from the CNS to the effector
  • Relay neurones
    Pass the impulses from the sensory neurones to the motor neurones
  • Effector
    Can be a muscle or a gland, carries out the response
  • Impulses can only travel in one direction along the neurones
  • Neurones
    • They are a specialised type of cell, elongated to allow impulses to travel long distances in the body
  • Reflex arc
    Simple and consists of only three neurones
  • Reflex actions
    Rapid, involuntary responses to changes in the environment
  • Effector
    May be a muscle or a gland
  • Receptor cells
    Detect stimuli and are found within sense organs
  • Reflex actions are very important in helping animals survive
  • Dendrons & dendrites
    • Allow connections between neurons or to receptors
  • Axon
    An extension of one cytoplasm, that carries nerve impulses away from the cell body
  • Myelin sheath
    • Provides electrical insulation
    • Allows nerve impulses to jump along the axon from node to node
  • Nodes of Ranvier
    Allow nerve impulses to travel faster
  • Cell body
    Produces all the protein for the dendrites, axons, and synapses & contains specialised organelles such as mitochondria
  • Nerve endings
    Form many connections (synapses) with other neurons or effector organs
  • Nucleus
    Controls activity in the neurons
  • Cytoplasm
    Where all chemical reactions happen in the cell
  • Cell membrane
    Controls what goes in and out of the cell