myelination

• Saltatory conduction?

  When nerve fibre is myelinated:

  • Myelin sheath insulates most of membrane -> separate from ECF
  • Thus , depolarisation only occur at Nodes of Ranvier -> only area allow ion exchanges between ICF and ECF
  • action potential -> jumps from one node to next.
• Continuous Conduction?

  When a nerve fibre is unmyelinated:

  • depolarisation of one area of membrane -> area adjacent to also depolarise
  • creates domino effect -> propagates action potential along fibre
• main functions of myelination?

  insulation, protection of fibre from damage, Accelerating rate of impulse transmission along axon