[1] These nerves control the muscles of the face and neck and are involved in facial expression, mastication, swallowing, and other motor functions.

The majority of fibres of the corticospinal tract cross over in the medulla oblongata, resulting in muscles being controlled by the opposite side of the brain.

The corticospinal fibers converge to a point when descending from the internal capsule to the brain stem from multiple directions, giving the impression of an inverted pyramid.

The term pyramidal tracts refers to upper motor neurons that originate in the cerebral cortex and terminate in the spinal cord (corticospinal) or brainstem (corticobulbar).

[4] The nerve axons travel from the cortex through the posterior limb of internal capsule, through the cerebral peduncle and into the brainstem and anterior medulla oblongata.

These axons travel down the tracts in the white matter of the spinal cord until they reach the vertebral level of the muscle that they will innervate.

[2] Nerve axons of the lateral corticospinal tract that did not cross over in the medulla oblongata do so at the level of the spinal cord they terminate in.

About 3% of nerve axons have a much larger diameter (16μm) and arise from Betz cells, mostly in the leg area of the primary motor cortex.

[5] With the exception of lower muscles of facial expression, all functions of the corticobulbar tract involve inputs from both sides of the brain.

[citation needed] In National Lampoon's European Vacation, the Griswold family wins a vacation on a game show called Pig in a Poke when their opponents fail to correctly answer a question about the pyramidal tracts, despite Clark Griswold (played by Chevy Chase) mistakenly answering that they are a housing development outside Cairo.