Precentral gyrus

• The gyrus in the brain that lies just anterior to the central sulcus; contains the primary motor cortex.

Primary motor cortex

• The precentral gyrus is commonly known as the primary motor cortex.

Anatomy

• It is a frontal lobe region of the brain involved for the regulation of voluntary movement. Just anterior to the central sulcus, which divides it from the primary somatosensory cortex, is the precentral gyrus.
• Further subdivisions of the precentral gyrus include the primary motor cortex and the supplementary motor region.

Motor control

• The primary motor cortex regulates delicate and precise motions of the body, including those of the fingers, hands, feet, and tongue.
• Different sections of the primary motor cortex correspond to various body parts.
• For instance, the region of the main motor cortex responsible for directing the movements of the hand and arm are adjacent to one another.

Supplementary motor region

• Located slightly above the primary motor cortex, the supplementary motor region is responsible for the planning and execution of voluntary motions. It plays a role in movement initiation, movement sequence selection, and movement coordination.

Lesions

• A variety of motor impairments, including weakness, paralysis, and problems with fine motor control, can result from damage to the precentral gyrus.
• Lesions in the primary motor cortex can cause contralateral hemiparesis (weakness or paralysis on one side of the body), whereas lesions in the supplementary motor area might cause trouble beginning and coordinating movement.

Conclusion

• Overall, the precentral gyrus plays an essential role in the regulation of voluntary movement, and any injury to this region can lead to major motor impairments.

Additional images

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  Precentral gyrus highlighted in green on coronal T1 MRI images
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  Precentral gyrus highlighted in green on sagittal T1 MRI images
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  Precentral gyrus highlighted in green on transversal T1 MRI images

See also

• Corticospinal tract
• Motor cortex
• List of regions in the human brain

References

1. Jain, N., & Behari, S. (2016). Precentral gyrus: Anatomy, functions, and clinical correlations. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia, 25, 14-20.
2. Penfield, W., & Rasmussen, T. (1950). The cerebral cortex of man: a clinical study of localization of function. Macmillan.
3. Rizzolatti, G., & Luppino, G. (2001). The cortical motor system. Neuron, 31(1), 889-901.