• Sleep cycles
  At night, you go through cycles of deep sleep followed by shallow ...

• Sweet dreams
  Shallow sleep is also called REM sleep. This stands for Rapid Eye ...

• Nervous system
  Your brain, nerves and spinal cord form your body's nervous system. ...

• Taking a back road
  Your delicate spinal cord runs down a tunnel of holes in your ...

• What a nerve!
  Nerves are made up of bunches of hundreds of long fibres belonging to ...

• Crossing the gap
  The axon of one neurone does not actually touch the dendrites of the ...

• Lightning reactions
  Some nerve signals travel along your nerves at speeds of about 120m ...

• Automatic action
  A separate set of nerves controls automatic functions, such as ...

• Amazing But True
  An adult has some 75km (46 miles) of nerves, enough to stretch over ...

• Go to sleep
  If you have an operation, or a filling at the dentist's, you are ...