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|Column of Clarke|
|Diagram showing a few of the connections of afferent (sensory) fibers of the posterior root with the efferent fibers from the ventral column and with the various long ascending fasciculi. (Dorsal nucleus labeled at center right.)|
|Latin||nucleus thoracicus posterior, nucleus dorsalis|
|Gray's||subject #185 758|
|Schematic of spinal cord grey matter showing location of the Dorsal Nucleus|
It occupies the medial part of the base of the posterior column and appears on the transverse section as a well-defined oval area.
It begins below at the level of the second or third lumbar nerve, and reaches its maximum size opposite the twelfth thoracic nerve. Above the level of the ninth thoracic nerve its size diminishes, and the column ends opposite the last cervical or first thoracic nerve.
It is represented, however, in the other regions by scattered cells, which become aggregated to form a cervical nucleus opposite the third cervical nerve, and a sacral nucleus in the middle and lower part of the sacral region.
Nerve cells in Clarke’s column are most abundant between the lower thoracic and upper lumbar segments. Cell bodies are of medium size and oval- or pyriform-shape. Some cells can be as large as anterior horn cells; the nuclei of these larger cells are often found on the periphery of the cell.
Clarke’s column is a major relay center for unconscious proprioception. Sensory information for muscle spindles and tendon organs synapses onto posterior root ganglion, which in turn synapses onto Clarke’s column. From Clarke’s column, information continues rostrally until it reaches the cerebellar cortex. This relay pathway is generally known as the spinocerebellar tract.
Brain and spinal cord: neural tracts and fasciculi
| Template:Central nervous system navs
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