Spinal cord

• spinal nerves from c1-c7 exit above corresponding vertebrae
• c8 exits below c7 above t1
• T1-12 exit below corresponding vertebrae
• 8 cervical 12thoracic 5 lumbar 5 sacral 1 coccygeal
• spinal cord in adults ends at L1-L2. subarachnoid space ends at S2
• csf sample is taken between L3 - L4 OR L4 - L5( cauda equina)
• in csf collection needle passes through

  skin

  fascia and fat

  supraspinous ligament

  interspinous ligament

  ligamentum flavum

  epidural space

  dura matter

  arachnoid matter

  subarachnoid space