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 (Brodmann area 4).

[1] The corticobulbar tract however also includes fibres from disparate regions from across the cerebral cortex (not limited to the frontal lobes).

The corticobulbar fibers exit at the appropriate level of the brainstem to synapse on the lower motor neurons of the cranial nerves.

This is in contrast to the corticospinal tract in which the cerebral cortex connects to spinal motor neurons, and thereby controls movement of the torso, upper and lower limbs.

The corticobulbar tract directly innervates the nuclei for cranial nerves V, VII, IX, and XII.