The Spinal Cord II

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Spinal cord I | Main Anatomy Index | Blood supply of the spinal cord

Last updated 30 March 2006

Spinal Cord II

Spinal Grey Matter

Posterior Horn

  1. The substantia gelatinosa;
  2. And the body of the posterior horn.


The Substantia Gelatinosa


Lissauer's Tract


The Body of the Posterior Horn (Nucleus Proprius)

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Anterior Horn

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Intermediate Grey Matter


Nucleus Dorsalis (Clarke's nucleus)

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Rexed's Laminae

The same system has since been applied to the cords of other mammals, including humans.

Nucleus Levels Lamina Function
Marginal zone All I Some spinothalamic tract cells
Substantia gelatinosa All II Modulate pain and temperature
Body of posterior horn All III-VI Sensory processing
Nucleus dorsalis T1-L2/L3 VII Posterior spinocerebellar tract cells
Intermediolateral column T1-L2/L3 VII Preganglionic sympathetics
Sacral parasympathetic nucleus S2-S4 VII Preganglionic parasympathetics --> pelvic viscera
Accessory nucleus Medulla-C5 IX Motor neurons --> trapezius and sternocleidomastoid
Phrenic nucleus C3-C5 IX Motor neurons --> diaphragm


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Spinal White Matter

  1. Long ascending fibres projecting to the thalamus, the cerebellum, or various brainstem nuclei;
  2. Long descending fibres projecting from the cerebral cortex or from various brainstem nuclei to the spinal grey matter;
  3. Shorter propriospinal fibres interconnecting various spinal cord levels, such as the fibres responsible for the co-ordination of flexor reflexes.


Ascending Pathways


Pathways to the Thalamus and Cortex

  1. The posterior column-medial lemniscus pathway;
  2. And the spinothalamic tract.
  1. Most somatosensory information travels in more than one pathway;
  2. Tracts in the posterior half of the cord ascend uncrossed whereas those in the anterior half of the cord cross the midline as they form.
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Posterior Columns


First Order Fibres


Second Order Fibres


Third Order Fibres


Somatotopic Organisation

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Spinothalamic Tract

First Order Fibres


Second Order Fibres

  1. Itch (and probably tickle) sensations;
  2. Pressure sensations from bladder and bowel;
  3. And sexual sensations.
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Pathways to the Cerebellum

Posterior Spinocerebellar Tract

First Order Fibres


Second Order Fibres

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Anterior Spinocerebellar Tract

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Descending Pathways

Corticospinal Tract

Lateral Corticospinal Tract


Anterior Corticospinal Tract

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Rubrospinal Tract


Vestibulospinal Tracts

Lateral Vestibulospinal Tract


Medial Vestibulospinal Tract


Reticulospinal Tracts

Click here to go to the entry under the Reticular Formation.

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Michael Tam (c) 1999