motor cortex(redirected from Secondary motor cortex)
Also found in: Dictionary, Thesaurus, Encyclopedia.
the region of the cerebral cortex most nearly immediately influencing movements of the face, neck and trunk, and upper and lower extremities; it corresponds approximately to Brodmann areas 4 and 6 of the precentral gyrus and anterior paracentral gyrus, and immediately adjacent portions of the superior and middle frontal gyri; its effects on the motor neurons innervating the skeletal musculature are mediated by corticospinal fibers (pyramidal tract) and corticonuclear fibers and are particularly essential for the human capacity to perform finely graded movements of the extremities, especially the upper.
mo·tor cor·tex(mō'tŏr kōr'teks)
motor cortexThe part of the surface layer of each hemisphere of the main brain (cerebrum) in which voluntary movement is initiated. These areas can be mapped out to show which parts of them are responsible for movement of any particular parts of the body. The map resembles a distorted and inverted human figure.
motor cortexthe part of the cerebral cortex of the brain that controls the motor functions.
Rolando,Luigi, Italian anatomist, 1773-1831.
fissure of Rolando - a double S-shaped fissure extending obliquely upward and backward on the lateral surface of each cerebral hemisphere at the boundary between frontal and parietal lobes. Synonym(s): central sulcus
rolandic epilepsy - a benign autosomal dominant form of epilepsy occurring in children.
Rolando angle - the angle at which the fissure of Rolando meets with the midplane.
Rolando area - the region of the cerebral cortex most immediately influencing movements of the face, neck and trunk, arm, and leg. Synonym(s): motor cortex
Rolando cells - the nerve cells in Rolando gelatinous substance of the spinal cord.
Rolando column - a slight ridge on either side of the medulla oblongata related to the descending trigeminal tract and nucleus.
Rolando gelatinous substance - the apical part of the posterior horn of the spinal cord's gray matter, composed largely of very small nerve cells. Synonym(s): gelatinous substance
Rolando tubercle - a longitudinal prominence on the dorsolateral surface of the medulla oblongata along the lateral border of the tuberculum cuneatum. Synonym(s): tuberculum cinereum
Area of the frontal lobe of the brain just anterior to the central sulcus which is responsible for voluntary movements of the eyes (as well as other voluntary movements of other parts of the body). The motor cortex in each hemisphere controls mainly muscles on the opposite side of the body. It is laid out according to the parts of the body, with the region controlling the feet at the top and the region controlling the legs, the trunk, the arms and the head in descending order.