The leading role in the development of the child's body in the first year of life belongs to the central nervous system. On the one hand, it ties together all the internal organs and regulates the processes occurring in them, on the other hand, it acts as an intermediary between the organism as a whole and the environment.
By the time of birth of the spinal cord is the most developed in the child, as the simplest reflex movements indicate.
With regard to the brain, its relative mass is large enough: V8 from the total body weight. In the first year of life, nerve cells are formed within each layer of the cortex in both hemispheres.