Which brain region contains the primary motor cortex that controls voluntary movement?

The precentral gyrus contains the primary motor cortex that controls voluntary movement.

Located in the frontal lobe immediately in front of the central sulcus, the precentral gyrus houses Brodmann area 4, the primary motor cortex. Neurons there send commands through descending pathways, especially the corticospinal tract, to motor circuits in the brainstem and spinal cord.

The body is represented in an orderly, upside-down arrangement across this cortex, often called the motor homunculus. Areas requiring fine control, such as the hands and face, occupy disproportionately large portions compared with areas needing less precise movement.

The precentral gyrus does not work alone. Premotor and supplementary motor areas help plan and prepare actions, while the basal ganglia and cerebellum contribute selection, timing, coordination, and error correction. The postcentral gyrus, on the opposite side of the central sulcus, is primarily sensory rather than motor.