Search results
Results from the WOW.Com Content Network
The motor cortex can be divided into three areas: 1. The primary motor cortex is the main contributor to generating neural impulses that pass down to the spinal cord and control the execution of movement. However, some of the other motor areas in the brain also play a role in this function.
At the primary motor cortex, motor representation is orderly arranged (in an inverted fashion) from the toe (at the top of the cerebral hemisphere) to mouth (at the bottom) along a fold in the cortex called the central sulcus. However, some body parts may be controlled by partially overlapping regions of cortex.
Central structures include cerebral cortex, brainstem, spinal cord, pyramidal system including the upper motor neurons, extrapyramidal system, cerebellum, and the lower motor neurons in the brainstem and the spinal cord. [3] The motor system is a biological system with close ties to the muscular system and the circulatory system.
The corticospinal tract is a white matter motor pathway starting at the cerebral cortex that terminates on lower motor neurons and interneurons in the spinal cord, controlling movements of the limbs and trunk. [1] There are more than one million neurons in the corticospinal tract, and they become myelinated usually in the first two years of life.
The cortex is divided into two main functional areas – a motor cortex and a sensory cortex. [23] The primary motor cortex , which sends axons down to motor neurons in the brainstem and spinal cord, occupies the rear portion of the frontal lobe, directly in front of the somatosensory area.
The spinal cord functions primarily in the transmission of nerve signals from the motor cortex to the body, and from the afferent fibers of the sensory neurons to the sensory cortex. It is also a center for coordinating many reflexes and contains reflex arcs that can independently control reflexes. [1]
The pyramidal tracts include both the corticobulbar tract and the corticospinal tract.These are aggregations of efferent nerve fibers from the upper motor neurons that travel from the cerebral cortex and terminate either in the brainstem (corticobulbar) or spinal cord (corticospinal) and are involved in the control of motor functions of the body.
The right half of the motor area controls the left side of the body, and vice versa. Two areas of the cortex are commonly referred to as motor: Primary motor cortex, which executes voluntary movements [69] Supplementary motor areas and premotor cortex, which select voluntary movements. [70] In addition, motor functions have been described for: