Classification of the nervous system
Last reviewed: 23.04.2024
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According to the topographic principle, the human nervous system is conditionally divided into central and peripheral.
The central nervous system (CNS) includes the spinal cord and the brain, which consist of gray and white matter. The gray matter of the spinal cord and the brain are accumulations of nerve cells together with the closest branches of their processes. The white matter is the nerve fibers, the processes of the nerve cells that have the myelin sheath (hence the white color of the fibers). Nerve fibers form the pathways of the spinal cord and brain and connect different parts of the central nervous system and various nuclei (nerve centers) with each other.
The peripheral nervous system consists of rootlets, spinal and cranial nerves, their branches, plexuses and nodes, as well as nerve endings lying in various parts of the human body, in its organs and tissues.
According to another, anatomical and functional classification, the unified nervous system is also conditionally divided into two parts: somatic and autonomous, or vegetative. The somatic nervous system ensures the innervation of mainly the body - soma, namely: skin, skeletal (arbitrary) muscles. This department of the nervous system performs the functions of communication of the organism with the external environment with the help of skin sensitivity and sense organs.
Autonomous (vegetative) nervous system innervates all the insides, glands, including endocrine, involuntary musculature of organs, skin, vessels, heart, and regulates metabolic processes in all organs and tissues.
The autonomic nervous system is in turn subdivided into a parasympathetic and sympathetic part. In each of the parts, as in the somatic nervous system, the central and peripheral parts are distinguished.
This division of the nervous system, despite its conventionality, has developed traditionally and seems to be quite convenient for studying the nervous system as a whole and its individual parts. In this connection, in the future, we will also adhere to this classification in the presentation of the material.
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