Precentral gyrus
Updates to Article Attributes
The precentral gyrus, also known as the primary motor cortex, is a very important structure involved in executing voluntary motor movements.
Gross anatomy
The precentral gyrus is a vertically oriented cerebral convolution situated in the posterior portion of the frontal lobe. It is located immediately anterior to the central sulcus (fissure of Rolando), running parallel to it. It extends from the most superior aspect of the hemisphere down to the Sylvian fissure1-2.
Anterior to the precentral gyrus lie, separated by the precentral sulcus, lie a set of areas composing the lateral premotor cortex and the supplemental motor area.
Posteriorly, liesseparated by the central sulcus, lies the primary somatosensory cortex (primary somatosensory cortex). Mesially.
Medially and inferiorly, it is bound by the cingulate gyrus. Laterally
Laterally and inferiorly, it is bound the SylivanSylvian fissure, forming a lip over the insula called the operculum3.
AsIn the primary motor cortexprecentral gyrus, large neurons known as Betz cells send efferent axons from the precentral gyrus that terminate on the contralateral motor cranial and spinal nuclei. The functional organisation of the precentral gyrus is such that neuronsclusters of Betz cells are somatotopically represented by an inverted homunculus. In this wayTherefore, the head head and face regions are innervated by the inferior portion of the precentral gyrus. Conversely, the lower limbs are innervated by the superior portionsportion.4
-<p>The <strong>precentral gyrus</strong>, also known as the primary motor cortex, is a very important structure involved in executing voluntary motor movements. </p><h4>Gross anatomy</h4><p>The precentral gyrus is a vertically oriented cerebral convolution situated in the posterior portion of the frontal lobe. It is located immediately anterior to the central sulcus (fissure of Rolando), running parallel to it. It extends from the most superior aspect of the hemisphere down to the Sylvian fissure<sup>1-2</sup>. </p><p>Anterior to the precentral gyrus lie a set of areas composing the lateral premotor cortex. Posteriorly, lies the somatosensory cortex (primary somatosensory cortex). Mesially, it is bound by the cingulate gyrus. Laterally, it is bound the Sylivan fissure, forming a lip over the insula called the operculum<sup>3</sup>. </p><p>As the primary motor cortex, large neurons known as Betz cells send efferent axons from the precentral gyrus that terminate on motor cranial and spinal nuclei. The functional organisation of the precentral gyrus is such that neurons are somatotopically represented by an inverted homunculus. In this way, the head and face regions are innervated by the inferior portion of the precentral gyrus. Conversely, the lower limbs are innervated by the superior portions. </p>- +<p>The <strong>precentral gyrus</strong>, also known as the primary motor cortex, is a very important structure involved in executing voluntary motor movements. </p><h4>Gross anatomy</h4><p>The precentral gyrus is a vertically oriented cerebral convolution situated in the posterior portion of the frontal lobe. It is located immediately anterior to the <a href="/articles/central-sulcus">central sulcus (fissure of Rolando)</a>, running parallel to it<sup>1-2</sup>. </p><p>Anterior to the precentral gyrus, separated by the precentral sulcus, lie a set of areas composing the lateral premotor cortex and the supplemental motor area. </p><p>Posteriorly, separated by the central sulcus, lies the primary somatosensory cortex .</p><p>Medially and inferiorly, it is bound by the <a href="/articles/cingulate-gyrus">cingulate gyrus</a>.</p><p>Laterally and inferiorly, it is bound the <a href="/articles/sylvian-fissure">Sylvian fissure</a><sup>3</sup>. </p><p>In the precentral gyrus, large neurons known as <a href="/articles/betz-cells">Betz cells</a> send efferent axons that terminate on the contralateral motor cranial and spinal nuclei. The functional organisation of the precentral gyrus is such that clusters of Betz cells are somatotopically represented by an inverted <a href="/articles/homunculus">homunculus</a>. Therefore, head and face regions are innervated by the inferior portion of the precentral gyrus. Conversely, the lower limbs are innervated by the superior portion.<sup>4</sup></p>
References changed:
- 1. Encyclopedia of Clinical Neuropsychology. Springer. ISBN:0387799486. <a href="http://books.google.com/books?vid=ISBN0387799486">Read it at Google Books</a> - <a href="http://www.amazon.com/gp/product/0387799486">Find it at Amazon</a><span class="auto"></span>
- 4. Rivara CB, Sherwood CC, Bouras C et-al. Stereologic characterization and spatial distribution patterns of Betz cells in the human primary motor cortex. Anat Rec A Discov Mol Cell Evol Biol. 2003;270 (2): 137-51. <a href="http://dx.doi.org/10.1002/ar.a.10015">doi:10.1002/ar.a.10015</a> - <a href="http://www.ncbi.nlm.nih.gov/pubmed/12524689">Pubmed citation</a><span class="auto"></span>
- 3. Parent A, Carpenter MB. Carpenter's Human neuroanatomy. Williams & Wilkins. ISBN:0683067524. <a href="http://books.google.com/books?vid=ISBN0683067524">Read it at Google Books</a> - <a href="http://www.amazon.com/gp/product/0683067524">Find it at Amazon</a><span class="auto"></span>
- 2. Encyclopedia of Autism Spectrum Disorders:5 volume set. Springer. ISBN:1441916970. <a href="http://books.google.com/books?vid=ISBN1441916970">Read it at Google Books</a> - <a href="http://www.amazon.com/gp/product/1441916970">Find it at Amazon</a><span class="auto"></span>
Tags changed:
- neuroanatomy
- precentral gyrus
- motor strip
- primary motor cortex
- brain
Sections changed:
- Anatomy
Systems changed:
- Central Nervous System
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