Neurone structures

• 3 Key features of neurones

  1. Cell body
  2. dendrons
  3. axons
• What is the cell body of a neurone 


  It contains the nucleus surrounded by the cytoplasm
• What are the dendrons in a neurone

  Short extensions which come from the cell body, they transmit electrical impulses towards the cell body
• What are the axons in a neurone

  Elongated nerve fibres which transmit nerve impulses away from the cell body
• What is this neurone

  Relay neurone

  
• What is this neurone

  Motor neurone

  
• What is this neurone

  Sensory neurone

  
• What is a sensory neurone

  They transmit impulses from sensory receptor and have one axon and one dendrimer
• What is the axon of some neurones covered in

  Myelin sheath
• What is the myelin sheath made of

  Many layers of plasma membrane
• What produces the layers of membranes

  Schwann cells
• how to Schwann cells produce the layers of membranes

  By growing round the axon many times
• What happens each time a Schwann cell grows around a axon

  A double layer of phospholipid bilayer is laid down
• When a schwann cell stops growing how many layers are there

  About 20 layers of membrane
• How fast can myelinated neurones conduct an impulse compared to non myelinated

  100m per second compared to 1m per second
• What is the gap between each Schwann cell called


  Node of Ranvier
• How big is the node of Ranvier

  2-3um
• How does the impulse travel of a myelinated sheath

  From one node to the next node
• What does ms do

  The immune system at ems healthy body tissue resulting in the thinning/complete loss of myelin sheath and eventually breaks down the axons of neurones