Fasciculus cuneatus

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Fasciculus cuneatus

Fasciculus cuneatus is 3b, in blue at upper right.

Diagram of the principal fasciculi of the spinal cord.
Latin	fasciculus cuneatus medullae spinalis
Gray's	subject #185 763
Dorlands/Elsevier	f_03/12355858

The fasciculus cuneatus (tract of Burdach) 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 and cuneate nuclei.

The Fasciculus cuneatus transmits fine touch, fine pressure, vibration and proprioception information from spinal nerves located in dermatomes C₁ through T₆. 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 Thalymus 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.	Superior terminations of the posterior fasciculi of the medulla spinalis.	The sensory tract.
Upper part of medulla spinalis and hind- and mid-brains; posterior aspect, exposed in situ.

[edit] External links

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

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.

v • d • e

Anatomy of torso (primarily): the 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

spinal nerve: dorsal root, dorsal root ganglion, dorsal ramus, ventral root, ventral ramus, sympathetic trunk, ramus communicans (gray, white)

gray 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)