Motor-Sensory Cortices

The motor cortex is the side of the brain which controls voluntary muscles. The somatosensory cortex is the side of the brain which receives and analyzes sensory impulses from all parts of the body. The motor cortex governs the body's response to messages from the outside world. The motor nerves twine through muscle fibers like a root system that ends in clusters called "motor end plates". These fibers start muscle contractions by means of chemical messengers. The two sides of the brain, called hemispheres, are different in size, shape and the roles they play. The right hemisphere controls the motor responses in the left side of the body and the left hemisphere controls the right side. In most people, the left brain seems to be good at language, mathematics and logical thinking. The right side measures spatial perception (the appreciation of art and music), creativity, and even intuitive thinking.