350
►Brain
►►
B lo o d ve sse ls
C ra n ia l base
C ra n ia l nerves
M eninges
P arts of the brain
Pathways of the spinal cord
Gyrus precentralis
Fibrae corticospinales
Corpus striatum
Thalamus
Substantia nigra
Nuclei pontis
Fibrae pontocerebellares
Tractus bulboreticulospinalis etc,
(Tractus cerebellorubralis)
Cerebellum, Nucleus dentatus
Tractus rubrospinalis
Tractus reticulospinalis
Tractus vestibulospinalis
Tractus tectospinal is
Cornu anterius
Radix anterior
[motoria]
(Tractus rubrothalamicus)
Nucleus ruber
N spinalis
Fig. 615
Pathways of the motor system.
* Motor nuclei of cranial nerves
Descending pathways
The motor system comprises a targe number of nuclear regions and tracts. The "motor final path" are the motoneurons.
Despite the extraordinary complexity of these circuits, the traditional organisation will be maintained for didactic reasons.
[So-called] Pyramidal tract
1
(central] neuron (crossed)
From the cerebral cortex through the internal capsule and the cerebral peduncles to interneurons within the anterior
and posterior column (lateral corticospinal tract, anterior corticospinal tract, perikarya in the precentral gyrus).
Branching off of fibres to the nuclei of the cranial nerves (corticonuclear fibres and bulbar corticonuclear fibres).
2
(peripheral) neuron (motor end pathway, a-motoneurons]
From the anterior horn to the motor end plates of the skeletal musculature (motoneurons, perikarya in the anterior
horn).
(So-catted) Extrapyramidal motor system
1
central neurons (crossed and uncrossed)
From the cerebral cortex, particularly the precentral gyrus and the adjacent cortical areas including synapses to the
basal ganglia, thalamus, subthalamic nucleus, red nucleus, substantia nigra, cerebellum, etc. and feedback loops to
the interneurons of the anterior column (rubrospinal tract, medial and lateral vestibulospinal tract, reticulospinal tract,
tectospinal tract).
2
,
peripheral neuron (motor end pathway, a-motoneurons)
From the anterior horn to the motor end-plates of the skeletal muscles (motoneurons; perikarya in the anterior horn).
