The brain can be categorized into telencephalon, mesencephalon, cerebellum and brainstem. The brain stem includes the midbrain, the pons, and the medulla oblongata, except for these, none of the others are part of the brain stem. 1. Telencephalon: i.e., the left and right cerebral hemispheres, with tortuous grooves on the surface of the brain and the surface covering the cerebral cortex, the telencephalon is divided into frontal, temporal, occipital, parietal, and insula lobes. The telencephalon is the highest nerve center of the human body, the projection area of various senses and the initiation site of movement, controlling human emotions, thinking and language. 2. Mesencephalon: The mesencephalon is located between the two cerebral hemispheres and above the midbrain, one on each side, with the third ventricle in the middle chamber. It is divided into the superior thalamus, dorsal thalamus, posterior thalamus, basal thalamus and hypothalamus. Its main function is to receive and transmit somatic and visceral sensations to the brain, and at the same time, it has endocrine function to regulate water metabolism and sugar metabolism. 3. Cerebellum: The cerebellum is located in the posterior fossa of the skull, and is divided into the anterior lobe, posterior lobe, and juxtaglomerular lobe. The cerebellum mainly maintains body balance, regulates muscle tone and coordinates random movements. Damage to the cerebellum can lead to imbalance, ataxia and motor tremor.