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Classification of the nervous system
Last reviewed: 06.07.2025
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Based on the topographic principle, the human nervous system is conventionally divided into central and peripheral.
The central nervous system (CNS) includes the spinal cord and brain, which consist of gray and white matter. The gray matter of the spinal cord and brain is a cluster of nerve cells together with the nearest branches of their processes. The white matter is nerve fibers, processes of nerve cells that have a myelin sheath (hence the white color of the fibers). Nerve fibers form the conductive pathways of the spinal cord and brain and connect different parts of the CNS and various nuclei (nerve centers) with each other.
The peripheral nervous system consists of roots, spinal and cranial nerves, their branches, plexuses and nodes, as well as nerve endings located in various parts of the human body, in its organs and tissues.
According to another, anatomical-functional, classification, the unified nervous system is also conditionally divided into two parts: somatic and autonomic, or vegetative. The somatic nervous system provides innervation mainly of the body - the soma, namely: the skin, skeletal (voluntary) muscles. This section of the nervous system performs the functions of connecting the organism with the external environment using cutaneous sensitivity and sensory organs.
The autonomic (vegetative) nervous system innervates all the internal organs, glands, including endocrine glands, involuntary muscles of organs, skin, blood vessels, heart, and also regulates metabolic processes in all organs and tissues.
The autonomic nervous system is in turn divided into parasympathetic and sympathetic parts. In each of the parts, as in the somatic nervous system, there are central and peripheral sections.
This division of the nervous system, despite its conventionality, has developed traditionally and seems quite convenient for studying the nervous system as a whole and its individual parts. In this regard, in the future we will also adhere to this classification in the presentation of the material.
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