- Spinal Cord 107
■ Th e posterior spinocerebellar tract originates from
aff erents of the lower trunk and lower limb, synapses
in the dorsal nucleus of Clarke, and enters the
cerebellum via the ipsilateral inferior cerebellar
peduncle.
■ Th e anterior spinocerebellar tract originates from
aff erents of the lower limb and enters the cerebellum
via the superior cerebellar peduncle.
■ Th e cuneocerebellar tract originates in the upper limb
and upper trunk and enters the cerebellum via the
ipsilateral inferior cerebellar peduncle.
■ Th e rostral spinocerebellar tract originates in the
upper limb and enters the cerebellum via the
ipsilateral inferior cerebellar peduncle.Major Ascending & Descending Tracts
■ P o s t e r i o r c o l u m n fi bers ascend the spinal cord
ipsilateral to their side of origin.
■ A n t e r o l a t e r a l s y s t e m fi bers ascend the spinal cord
contralateral to their side of origin.
■ Lateral corticospinal tract fi bers descend the spinal
cord contralateral to their side of origin.
■ Posterior column pathway: 1st order neuron in the
dorsal root ganglion, 2nd order neuron in the gracile
and cuneate nuclei, 3rd order neuron in the
ventrolateral posterior nucleus of the thalamus.
■ Anterolateral system: 1st order neuron in the dorsal
root ganglion, 2nd order neuron in the dorsal horn of
the spinal cord, 3rd order neuron in the ventrolateral
posterior nucleus of the thalamus.
■ Corticospinal tract: 1st order neuron in the motor
cortices (primarily), 2nd order neuron in the anterior
horn of the spinal cord.Spinocerebellar Pathways (Advanced)