Reflex arc

• Reflex arc:

  stimulus -> receptor -> sensory neurone -> relay neurone (co-ordinator) -> motor neurone -> effector -> response
• Reflex - a rapid, involuntary response to a stimulus
• A reflex helps you get out of danger quickly
• Reflex arc diagram

  A) receptor

  B) sensory neurone

  C) dorsal root ganglion

  D) dorsal root

  E) relay neurone

  F) ventral root

  G) motor neurone

  H) effector

  I) white matter

  J) grey matter

  K) central canal

  
• Spinal meninges

  A) pia mater

  B) arachnoid mater

  C) dura mater