The brain includes two hemispheres, the left hemisphere and the right hemisphere, and the endplate connecting the middle part of the two hemispheres, that is, the front end of the third ventricle. The cerebral hemisphere is covered with gray matter, called cerebral cortex, and its deep side is white matter, called medulla. The gray matter nuclei in medulla are basal ganglia. The two hemispheres of the brain are connected by huge fiber bundles.

The specific content includes five parts: cerebral lobe, functional orientation of cerebral cortex, deep structure of cerebral hemisphere, white matter of cerebral hemisphere, olfactory brain and limbic system.

The surface of the cerebral hemisphere is uneven and covered with grooves of different depths, and the convex part between the grooves is called the cerebral gyrus. On the dorsal side of the cerebral hemisphere, there is an oblique groove called lateral fissure. Above the lateral fissure, about in the center of the hemisphere, there is a sulcus called the central sulcus, from top to bottom. Each hemisphere is divided into four leaves. Before the central sulcus and above the lateral fissure, it becomes the frontal lobe, which is the largest of the four cerebral lobes, accounting for about one-third of the cerebral hemisphere; The part below the lateral fissure is called temporal lobe; The part behind the central sulcus and above the lateral fissure is called parietal lobe; After the parietal lobe and temporal lobe, the posterior part of the brain above the cerebellum is called the occipital lobe. All the above lobes extend to the inner surface and bottom surface of the hemisphere, and there are many sulcus in each lobe area, which contain various nerve centers and share different tasks, forming the division and specialization function of the cerebral cortex.