The primary motor cortex is located in the posterior portion of the frontal lobe. It works with other motor areas including the premotor cortex, the supplementary premotor area, the posterior parietal cortex, and several subcortical brain regions, to plan as well as execute movements. The primary motor cortex contains large neurons known as Betz cells which send long axons down the spinal cord. This area of the brain contains a rough map of the body parts controlled by partially overlapping regions of cortex arranged from the toe all the way to the mouth
The somatosensory cortex processes input from various systems in the body that are sensitive to touch. It is often thought of touch as being a single sense, but in reality there are several different sensory experiences involved. For example, there is specific sensitivity to pain and temperature. As a whole, the primary somatomotor cortex is extremely refined and highly sensitive which allows people to detect and interpret a numerous variety of sensations. It is located in the forebrain, within an area called the postcentral gyrus.