The Spinal Cord I

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General topography of the brain | Main Anatomy Index | Spinal cord II

Last updated 30 March 2006

The Spinal Cord I

Barr M. L., Kiernan J. A. (1988) The Human Nervous System, An Anatomical Viewpoint 5th Ed. J. B. Lippincott Company, Philadelphia, Pennsylvania, USA. 

  1. Initiate a spinal reflex;
  2. Or are relayed to the brain stem and cerebellum where they are used in various circuits.
  3. Sensory information is also transmitted to the thalamus and then the cerebral cortex, where it becomes part of the conscious experience --> emotional response.
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Gross Features of the Spinal Cord and Nerve Roots

  1. The vertebrae and their ligaments;
  2. And the meninges and a cushion of CSF.


The Denticulate Ligament


Epidural Space


Segmental Spinal Nerves and Gross Features

Cervical 8
Thoracic 12
Lumbar 5
Sacral 5
Coccygeal 1


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Development of Spinal Cord and Gross Features

  1. Spinal nerves from C1 through C7 leave the spinal canal through the intervertebral foramina above the corresponding vertebrae (the 1st and 2nd cervical nerves lie on the vertebral arches of the atlas and axis, respectively).
  2. The 8th cervical nerve passes through the foramen between C7 and T1 because there are 8 cervical cord segments and only 7 cervical vertebrae.
  3. From this point caudally, the spinal nerves leave the canal through foramina immediately below the pedicles of the corresponding vertebrae.
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Dorsal and Ventral Roots and Gross Features


The Cauda Equina


The Filum Terminale


Spinal Lumbar Puncture


Spinal Cord Enlargements


The Surface of the Spinal Cord

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Grey Matter and White Matter

Grey Matter

  1. The dorsal horns;
  2. The ventral horns;
  3. And an intermediate zone.


Neurons in the Spinal Grey Matter

White Matter


General Pattern of Grey and White Matter

  1. The amount of white matter increases in a caudal-to-rostral direction because fibres are added to ascending tracts and fibres leave descending tracts to terminate in the grey matter.
  2. There is increased volume of grey matter in the cervical and lumbosacral enlargements for innervation of the limbs.
  3. The small lateral horn of grey matter is characteristic of the thoracic and upper lumbar segments.
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Michael Tam (c) 1998