Corticobulbar tract | |
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Components and location of the corticobulbar tract.
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Details | |
Identifiers | |
Latin | tractus corticonuclearis, tractus corticobulbaris |
NeuroNames | ancil-371 |
Dorlands /Elsevier |
t_15/12816062 |
Anatomical terms of neuroanatomy
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The corticobulbar (or corticonuclear) tract is a two neuron white matter motor pathway connecting the motor cortex in the cerebral cortex to the Medullary pyramids, which are part of the brainstem's medulla oblongata (also called "bulbar") region, and are primarily involved in carrying the motor function of the non-oculomotor cranial nerves. The corticobulbar tract is one of the pyramidal tracts, the other being the corticospinal tract.
The corticobulbar tract originates in the primary motor cortex of the frontal lobe, just superior to the lateral fissure and rostral to the central sulcus in the precentral gyrus also known as Brodmann area 4. The tract descends through the corona radiata and genu of the internal capsule with a few fibers in the posterior limb of the internal capsule, as it passes from the cortex down to the midbrain. In the midbrain, the internal capsule becomes the cerebral peduncles. The white matter is located in the ventral portion of the cerebral peduncles, called the crus cerebri. The middle third of the crus cerebri contains the corticobulbar and corticospinal fibers. The corticobulbar fibers exit at the appropriate level of the brainstem to synapse on the lower motor neurons of the cranial nerves.