The brain occupies most of the space in the cranial cavity, and each hemisphere can be divided into frontal, parietal, temporal and occipital lobes, and deep structures such as the thalamus and basal ganglia, which perform different functions. The brain is closely connected to the brainstem, which in turn is connected to the cerebellum and spinal cord to form the central nervous system as a whole. If the nervous system is the “command” of the human body, then the brain should be the higher “command center”. In terms of structure and function, all the senses of the human body are transmitted through the sensory nervous system and eventually reach the brain, while all the random movements of the human body are “ordered” by the brain and sent down through the motor nervous system to the motor organs. Although visceral activity, vascular movement, glandular secretion, etc. are independently managed by the autonomic nerves (also known as the vegetative nerves), they are also regulated by the autonomic nerve centers in the brain. As for language, memory, thinking, intelligence, emotion, behavior and other higher neuro-psychic activities, they are functions unique to the brain itself. Therefore, the brain is like the “commander-in-chief” of the human body, which directs and coordinates the functional activities of the entire human body through the “command” of the nervous system. As you can imagine, if something goes wrong with the brain, the effects will be extensive, and even partial damage will cause some dysfunction in the human body.