Fasciculus cuneatus

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Fasciculus cuneatus
Fasciculus cuneatus is 3b, in blue at upper right.
Latin	fasciculus cuneatus medullae spinalis
Gray's	subject #185 763
System
MeSH	[1]
Diagram of the principal fasciculi of the spinal cord.

The fasciculus cuneatus (tract of Burdach, named for Karl Friedrich Burdach) is a bundle of nerves in the spinal cord which primarily transmits information from the arms. It is part of the posterior column-medial lemniscus pathway.

Contents 1 Physical characteristics 2 Information transmitted 3 Neurons 4 Additional images 5 See also 6 External links

[edit] Physical characteristics

The fasciculus cuneatus is triangular on transverse section, and lies between the fasciculus gracilis and the posterior column, its base corresponding with the surface of the medulla spinalis.

Its fibers, larger than those of the fasciculus gracilis, are mostly derived from the same source, viz., the posterior nerve roots.

Some ascend for only a short distance in the tract, and, entering the gray matter, come into close relationship with the cells of the dorsal nucleus; while others can be traced as far as the medulla oblongata, where they end in the gracile nucleus and cuneate nucleus.

[edit] Information transmitted

The Fasciculus cuneatus transmits fine touch, fine pressure, vibration and proprioception information from spinal nerves located in dermatomes C₁ through T₆.

[edit] Neurons

The Fasciculus cuneatus tract is composed of 1st order neurons that synapse onto 2nd order neurons in the brain stem.

The 2nd order neurons decussate in the brainstem and continue on to the thalamus where the 2nd order neurons synapse onto 3rd order neurons.

The 3rd order neurons carry the received signals to the somatosensory cortex where the signals, in the form of action potentials are interpreted.

[edit] Additional images

Decussation of pyramids.	Superficial dissection of brain-stem. Lateral view.
The sensory tract.	Superior terminations of the posterior fasciculi of the medulla spinalis.
Upper part of medulla spinalis and hind- and mid-brains; posterior aspect, exposed in situ.

[edit] See also

• Fasciculus gracilis
• Dorsal columns

[edit] External links

• Neuroanatomy at UW sc97/text/p1/Pathway.htm

Spinal cord

epidural space, dura mater, subdural space, arachnoid mater, subarachnoid space, pia mater, denticulate ligaments, conus medullaris, cauda equina, filum terminale, cervical enlargement, lumbar enlargement, anterior median fissure, dorsal root, dorsal root ganglion, dorsal ramus, ventral root, ventral ramus, sympathetic trunk, gray ramus communicans, white ramus communicans grey matter: central canal, substantia gelatinosa of Rolando, reticular formation, substantia gelatinosa centralis, interneuron, anterior horn, lateral horn, posterior horn (column of Clarke, dorsal spinocerebellar tract) white matter: anterior funiculus: descending (anterior corticospinal tract, vestibulospinal fasciculus, tectospinal tract), ascending (anterior spinothalamic tract, anterior proper fasciculus) lateral funiculus: descending (lateral corticospinal tract, rubrospinal tract, olivospinal tract), ascending dorsal spinocerebellar tract, ventral spinocerebellar tract, spinothalamic tract, lateral spinothalamic tract, anterior spinothalamic tract, spinotectal tract, posterolateral tract, lateral proper fasciculus, medial longitudinal fasciculus posterior funiculus: fasciculus gracilis, fasciculus cuneatus, posterior proper fasciculus

This page uses content from the English-language version of Wikipedia. The original article was at Fasciculus cuneatus. The list of authors can be seen in the page history. As with Psychology Wiki, the text of Wikipedia is available under the GNU Free Documentation License.