- Cuneate fasciculus
Fasciculus cuneatus Cuneate fasciculus is labeled in blue at upper right. Diagram of the principal fasciculi of the spinal cord. Latin fasciculus cuneatus medullae spinalis Gray's subject #185 763
The fasciculus cuneatus (tract of Burdach, named for Karl Friedrich Burdach) is a tract of nerves in the spinal cord which primarily transmits information from the arms. It is part of the posterior column-medial lemniscus pathway.
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.
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.
- Fasciculus gracilis
- Dorsal columns
Anatomy of torso (primarily): the spinal cord (TA 14.1.02, GA 9.749) External, dorsalPosterior median sulcus · Posterolateral sulcus Grey matter/
Rexed laminaeI–VI: Posterior hornVII: Lateral hornVIII–IX: Anterior hornX: OtherCentral gelatinous substance · Gray commissure
External, ventralAnterior median fissure · Anterolateral sulcus External, general Brain and spinal cord: neural tracts and fasciculi Sensory/
ascending3°: → Posterior limb of internal capsule → Postcentral gyrusFast/lateralSlow/medial
descendingPyramidalMidbrain tectum → Tectospinal tract → muscles of neck
direct: 1° (Motor cortex → Striatum) → 2° (GPi) → 3° (Lenticular fasciculus/Ansa lenticularis → Thalamic fasciculus → VL of Thalamus) → 4° (Thalamocortical radiations → Supplementary motor area) → 5° (Motor cortex)
indirect: 1° (Motor cortex → Striatum) → 2° (GPe) → 3° (Subthalamic fasciculus → Subthalamic nucleus) → 4° (Subthalamic fasciculus → GPi) → 5° (Lenticular fasciculus/Ansa lenticularis → Thalamic fasciculus → VL of Thalamus) → 6° (Thalamocortical radiations → Supplementary motor area) → 7° (Motor cortex)nigrostriatal pathway: Pars compacta → Striatum
CerebellarAfferentEfferentFastigial nucleus in Flocculonodular lobe/vestibulocerebellum → Vestibulocerebellar tract → Vestibular nucleusBidirectional:
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