Spinal Cord (CNS)

Spinal Cord (CNS)

1. Blood Supply

   • Vertebral Arteries
     • Anterior Spinal Artery (1)
     • Posterior Spinal Arteries (2)
   • Segmented Medullary Arteries
     • Fuses with Spinal Arteries
     • Artery of Adamkiewicz/ Great Anterior Segmental Artery
       • Blood Supply to Lower Lumbar and Sacral Region
   • Radicular Arteries
     • Doesn't Fuse w/ Spinal Arteries
   • Internal Vertebral Venous Plexus
     • Often an avenue of prostate cancer metastisis
     • Located in Epidural Fat

2. Location (2/3 of Vertebral Canal)

   • From medulla oblongata
     • To Conus Medularis (Tapers Between LV1-LV2)

3. Unique traits

   • Large Sensory and Motor Inputs= Cervical Enlargement @ C4-T1 Lumbar Enlargement @ T11-L1

4. COMPOSTITION

   • Gray Matter (nerve cell bodies)- Non-myelinated, inner
   • Meninges Covering
     • Dura (touch, fibrous connective tissue)
     • Arachnoid
       • Subdural Space (extends to SV2) on Superior; Subarachnoid Space Inferior (Location of CSF)
     • Pia (intimately connected to spinal tissue)
       • Denticulate Ligaments (21 Pair)
         • Laterally Anchors Spinal Cord in Subarachnoid Space Transverses Dorsal and Ventral Nerve Roots; Runs From Pia to the Dura
       • Filum Terminale
         • LV2-SV2; inferior prolongation of pia Blends with dura and continues inferiorly to attach to coccyx = coccygeal ligament
   • White Matter (Axons)- myelinated, outer

5. SPINAL NERVES (31 PAIRS)

   • Union of Doral and Ventral Roots; Located in Intervertebral Foramen
   • 8, 12, 5,5,1
   • Cauda Equina
     • L2-Co1; Dorsal and Ventral Roots of Lumbar and Sacral S.N. In the subarachnoid space/lumbar cystern below the conus Floats freely in CSF, not damaged during LP
   • Dermatome- Area of skin innervated by sensory fibers from a particular spinal nerve
   • Scleratome- area of bone innervated by a single S.N. Segment
   • Myotome- group of muscles innervated by motor fibers derived from a single S.N segment