NETTER - Neuroscience Flash Cards

Somatosensory System:
Spinocerebellar Pathways
1. Superior cerebellar peduncle
2. Cuneocerebellar tract
3. Inferior cerebellar peduncle
4. Lateral (accessory) cuneate nucleus
5. Rostral spinocerebellar tract (RSCT)
6. Ia primary afferent
7. Ib primary afferent
8. Dorsal spinocerebellar tract
9. Ventral spinocerebellar tract (VSCT)
Comment: Proprioceptive primary sensory axons from the joints,
tendons, and ligaments (represented in diagram by Ib afferents)
terminate on secondary sensory neurons (border cells, dorsal
horn neurons) of the ventral spinocerebellar tract and rostral
spinocerebellar tract, carrying information from the lower (T6 and
below) and upper (above T6) body, respectively. Proprioceptive
primary somatosensory axons from muscle spindles (represented
in diagram by Ia afferents) terminate on secondary sensory neurons
(Clarke’s nucleus and the lateral [external] cuneate nucleus) of the
dorsal spinocerebellar tract and cuneocerebellar tract, carrying
information from the lower (T6 and below) and upper (above
T6) body, respectively. The spinocerebellar tracts terminate
ipsilaterally in the cerebellar except for the ventral spinocerebellar
tract, which crosses once in the spinal cord through the anterior
white commissure, and then again in the cerebellum, effectively
conveying information to the ipsilateral cerebellum. The output of
the cerebellum also is conveyed, sometimes through two sets of
crossing fibers, back to the ipsilateral side. Thus, cerebellar lesions
generally result in ipsilateral symptoms.
Systemic Neuroscience See book 14.3