This diagram illustrates the main features of the corticobulbar pathway from the cortex to the brainstem motor nuclei, as viewed from the lateral surface of the brain and in coronal section through the motor cortex, as highlighted. For simplicity, only one component out of several to different cranial nerve nuclei is depicted.

 

KEY CONCEPTS:

 

• Two neuron sequence from the motor cortex to brainstem cranial nerve motor nuclei.
• First synapse is in the brainstem.
• Axons cross sides in the brainstem at several places depending on destination cranial nerve motor nucleus.
• Carries voluntary motor commands.
• The facial nerve motor nucleus receives some axons from both sides (serving muscles above eyes).