{"id":8826,"date":"2019-05-22T16:11:56","date_gmt":"2019-05-22T16:11:56","guid":{"rendered":"http:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/primary_motor_cortex\/"},"modified":"2019-05-22T16:11:56","modified_gmt":"2019-05-22T16:11:56","slug":"primary_motor_cortex","status":"publish","type":"post","link":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/primary_motor_cortex\/","title":{"rendered":"Primary motor cortex"},"content":{"rendered":"<p>Structurally, it encompasses the precentral gyrus in the cortical area frontal to the central sulcus in each hemisphere and extends in an anterior direction across the frontal lobes. &nbsp;A distinctive anatomical feature of the primary motor cortex is the presence of giant pyramidal cells in the fifth layer of the cerebral cortex [the largest neurons in the cortex and also referred to as Betz cells after their discoverer&nbsp;<a href=\"http:\/\/www.ncbi.nlm.nih.gov\/pubmed\/22075067\" data-editable-link=\"http:\/\/www.ncbi.nlm.nih.gov\/pubmed\/22075067?target=_self\" target=\"_self\" rel=\"noopener noreferrer\">Vladimir Aleksandrovich Betz<\/a>&nbsp;(1834-1894)]. &nbsp;Its axons form the corticospinal tract. &nbsp;As these neurons project to several other neurons, the &#8216;motor maps&#8217; are rather imprecise in that stimulation of a cortical region results in activity in a large number of muscles, and a given muscle can be activated by stimulation across a wide range of the cortex. &nbsp;The premotor cortex and supplementary motor area together form the secondary motor cortex.&nbsp;&nbsp;Functionally, expressed in terms of topographical representations (or motor maps), it generates contralateral face, arm, trunk, and leg movements. &nbsp; Furthermore, it is involved in the control of voluntary movements. &nbsp;Having extensive connections with the somatosensory cortex in&nbsp;the parietal lobe, it ensures that movements can be modulated via fast sensory feedback. &nbsp;Like the visual cortex, if has a columnar organization such that cells in each column control the same group of muscles while adjacent columns control opposing muscle groups. &nbsp;Such an arrangement facilitates lateral inhibitory interactions among adjacent columns (e.g., &nbsp;the &#8216;biceps column&#8217; inhibits the &#8216;triceps column&#8217; and vice versa).&nbsp;<\/p>\n<p>See <a href=\"agonist_muscle\">Agonist muscle<\/a>, <a href=\"antagonist_muscle\">Antagonist muscle<\/a>, <a href=\"cortical_lobes\">Cortical lobes<\/a>, Corticospinal tract (CST), Direct corticomotoneuronal connections or tracts, <a href=\"extrapyramidal_system\">Extrapyramidal system<\/a>, <a href=\"gyrus\">Gyrus<\/a>, <a href=\"motor_cortex\">Motor cortex<\/a>, <a href=\"premotor_cortex\">Premotor cortex<\/a>, <a href=\"somatosensory_cortex\">Somatosensory cortex<\/a>, <a href=\"supplementary_motor_area_-sma-\">Supplementary motor area (SMA)<\/a>, <a href=\"visual_cortex\">Visual cortex<\/a><\/p>\n<p><\/body><\/html><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Structurally, it encompasses the precentral gyrus in the cortical area frontal to the central sulcus in each hemisphere and extends in an anterior direction across the frontal lobes. &nbsp;A distinctive anatomical feature of the primary motor cortex is the presence of giant pyramidal cells in the fifth layer of the cerebral cortex [the largest neurons &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/primary_motor_cortex\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Primary motor cortex&#8221;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[2],"class_list":["post-8826","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-glossary","entry"],"_links":{"self":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts\/8826","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/comments?post=8826"}],"version-history":[{"count":0,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts\/8826\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/media?parent=8826"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/categories?post=8826"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/tags?post=8826"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}