Central Nervous System Facts



  • The central nervous system (CNS) is made up of the brain and the spinal cord (the nerves of the spine).
  • The CNS contains billions of densely packed interneurons – nerve cells with very short connecting axons.
  • The spinal cord, together with the brain and nerves, form the body’s central information system, making sure all its different parts work together efficiently. Thoracic net Sacral nerves Brain Spinal cord Cervical nerves Lumbar nerves
  • . The CNS sends out messages to more 0 ‘than 640 muscles around the body.
  • The CNS is cushioned from damage by a surrounding bath of liquid called cerebrospinal fluid.
  • There are 86 main nerves branching off the CNS.
  • There are 12 pairs of cranial nerves, and 31 pairs of spinal nerves.
  • Cranial nerves are the 12 pairs of nerves that branch off the CNS out of the brain.
  • Spinal nerves arc the 31 pairs of nerves that branch off the spinal cord.
  • The spinal nerves are made up of 8 cervical nerve pairs, 12 thoracic pairs, 5 lumbar pairs, 5 sacral pairs and one coccyx pair.
  • Many spinal nerves join up just outside the spine in five spaghetti junctions called plexuses.