Spinal Cord Function And Dysfunction Flashcards
Spinal cord segments
31 spinal segments
31 pairs of spinal nerves
- 8 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 1 coccygeal
Nerves leave the vertebral column through intervertebral foramina
Enlargements for innervation of the limbs:
- Cervical (C3-T1)
- Lumbar (L1-S3)
Discrepancy between spinal levels and vertebral levels
- C1-C7 nerves come out above C1-C7 bones
- C8 nerve come out below C7 bone
- From then on, all nerves come out below corresponding bone
Slide 4 [pic]
Meningeal coverings
Slide 5 [pic]
Dura mater
Arachnoid mater
Pia mater
In brain and spinal cords - they differ
There’s no space b between dura and skull, but there is between dura and vertebral column - anaesthetics can be injected into subarachnoid space. Lumbar punctures can also be performed.
Epidural/spinal anaesthetic
Slide 6 [pic]
Nerves are floating around - generally move out of the way if you stick a needle in
Tail end - bunch of nerves (cauda equina) and a filament (white, glistening - extension of the pia) tethers the nerves to the sacrum
Spinal block for e.g. C-section
Spinal cord sections
Slide 7 [pic]
Dermatomes and myotomes
Slide 8 [pic]
Dermatome = area of skin innervated by one single spinal nerve or spinal segment
Myotome = muscles innervated by one single spinal nerve or spinal segment
Cross section of the spinal cord
Slide 9-10 [pic]
Rootlets join together —> roots
Roots join together —> spinal nerve
Mixed spinal nerve = sensory and motor nerves
- Divide into smaller branches: posterior ramus (innervate skin at the back) and anterior ramus (larger branch that goes on to innervate everything else)
Root = nerve fibres of only one type (motor or sensory) Ramus = mixture of motor and sensory
Gray matter
Slide 11 [pic]
Where cell bodies are
Major tracts of the spinal cord
Slide 12 [pic]
Fasciculus = bundle Gracilis = lower limb Cunneatus = upper limb
Corticospinal tract
Slide 13 [pic]
85% = one side, 15% stay on the same side
Main sensory pathways
Slide 14 [pic]
Primary sensory = goes into spinal cord
Secondary = crosses over the other side of the body (either travel up to synapse or synapse at the same level)
Synapse between secondary and tertiary is always in the thalamus
Dorsal column pathways
Slide 15 [pic]
Discriminative touch, vibration, proprioception
Spinothalamic tract
Slide 16 [pic]
Pain and temperature
Comes into spinal cord, synapses at the level
Up to the thalamus
Reflex pathways
Slide 17 [pic]
Autonomic flow
Slide 18 [pic]
Thoracolumbar and sacral segments
in some parts of the cord - extra intermediate horn in the thoracc and lumbar cord = site of motor neurons of SNS
Autonomic functions
Slide 19 [pic]
