There are many neurons in the brain, which further form different functional conduction bundles, which in turn control the body, speech, consciousness, thinking activities and other vital signs. For example, the olfactory nerve, optic nerve, ophthalmic nerve, trigeminal nerve, etc., which mainly govern the sense of smell, vision and eye movement in the human body, including the facial nerve and the linguopharyngeal and vagus nerves, etc., can govern facial expressions and facial muscle activities and swallowing functions. In the control of the body, the upper and lower motor neurons are divided in the brain, that is, the pyramidal tract, through the conduction of the pyramidal tract, the brain becomes the command of movement, and further dominates the movement of the limbs, generally the left side of the brain dominates the movement of the right side of the limbs, and the right side of the brain dominates the movement of the left side of the limbs, often in a cross symmetrical manner.