NEURONES

• KEY FEATURES OF A NEURONE?

  • cell body
  • dendrons
  • dendrites
  • axon
  • Schwann cells
  • myelin sheath
  • nodes of Ranvier
  • axon terminal
• WHAT DOES THE CELL BODY DO?

  contain organelles and a nucleus (lots of RER for protein/ neurotransmitter production)
• WHAT DO DENDRITES DO?

  carry nerve impulses to cell body
• WHAT DOES AN AXON DO?

  single, long fibre that carries nerve impulses away from cell body
• WHAT DO SCHWANN CELLS DO?

  protect and provide insulation for axon, carry out phagocytosis and play a part in nerve regeneration
• WHAT DOES THE MYELIN SHEATH DO?

  cover axon, is made up of membranes of Schwann cells (rich in lipid called myelin)
• WHAT DO SENSORY NEURONES DO?

  transmit nerve impulses from a receptor to a relay/ motor neurone
• FEATURES OF A SENSORY NEURONE?

  • one long dendron
  • one axon
  • cell body in middle
• WHAT DOES A MOTOR NEURONE DO?

  transmit nerve impulses from relay neurone to an effector
• FEATURES OF A MOTOR NEURONE?

  • long axon
  • short dendrites
• WHAT DOES A RELAY NEURONE DO?

  transmit impulses between neurones
• FEATURES OF A RELAY NEURONE?

  • no myelin sheath
  • short axon