Like other animals, the human being is capable of perceiving and assimilating information from both the external space around him and from his own interior; capturing, consciously or unconsciously, the signals that the same body emits from any part of it.

The nervous system is in charge of receiving and emitting these signals, managing and organizing the various tasks and activities of the body. This task has made it the most complex structure working in the human body. But the fact that it is complicated to understand does not mean that we cannot understand, at least superficially, how it is and how it works. Next we will see what the parts of the nervous system are and what their tasks are .

What is the Nervous System and what parts does it have?

The nervous system has the function of organizing, coordinating and governing the tasks that the human body carries out , constituting a kind of internal network that encompasses the entire body.To do this, it uses a grouping of organs and structures whose fundamental task is to collect and process the stimuli and signals, coming from both inside and outside, in order to achieve an adequate interaction with everything that surrounds the person.

This whole is originated from nerve tissue of ectodermal origin, this means that it is part of all those parts of the body that were formed first in the embryo.

In addition, this nerve tissue is made up of cells called neurons , which are specialized cells that communicate by means of chemical and electrical signals that travel throughout the human body until they reach the brain, which processes them and sends a flying response to the rest of the body.

It has been found that the number of neurons that make up the brain is around 100.00 million.

There are several ways to study and divide the human nervous system, this article will focus on the anatomical point of view. From this perspective this complex structure is formed by the central nervous system (CNS), which comprises the brain and spinal cord; and the peripheral nervous system (PNS) which is composed of all the nerves that start from the CNS and extend throughout the body.

The central nervous system (CNS)

The central nervous system has a number of peculiarities of its own. Some of these are:

  • Its most important organs are highly protected from the external environment, specifically by three membranes called meninges.
  • The functional cells of the central nervous system are grouped into two different organizations: white matter and gray matter.
  • The means of transmission of the information is through small holes in the brain and spinal cord, within which is the cerebrospinal fluid.

As we saw earlier, the central nervous system is made up of two different structures: the brain and the spinal cord.

1. Brain

The brain is the structure of the central nervous system inside the skull . This set of organs dominates all aspects of the body, including all the functions both voluntary and involuntary that a person can do.

Anatomically speaking , the brain includes the cerebrum, cerebellum and brain stem , which are also made up of other structures explained below.

1.1. Brain

It is the best known organ in this whole system and also the one with the most considerable size.

The brain is divided into two large hemispheres, the left and the right hemisphere , and in between which is the interhemispheric cleft. These two hemispheres also communicate by means of a bundle of nerve fibres called the corpus callosum.

The outer area of the brain is known as the cerebral cortex , formed from matter and grey, which takes the form of folds called convolutions. Beneath this layer of grey matter is white matter. In addition, the grey matter is also part of other structures such as the thalamus, caudate nucleus and hypothalamus.

Among many other functions, the brain is in charge of processing information from the different senses, as well as controlling movement, cognition, emotions, memory and learning.

1.2. Cerebellum

Located at the bottom and back of the brain, the cerebellum is responsible for integrating the sensory and motor processes of the human body .

It is connected to other encephalic structures and to the spinal cord by means of an infinite number of nerve beams, so that it is able to participate in all the signals that the cortex sends to the locomotive system.

Recent studies have also revealed that the cerebellum may be involved in other functions, including those related to cognitive and language processing, learning, and even the processing of other sensory stimuli such as music.

1.3. Brain stem

Also known as the brain stem or brainstem, it is the major communication pathway between the brain, spinal cord and peripheral nerves. Likewise, this system formed by gray and white matter is capable of controlling various tasks such as breathing or heart rate.

The structures that form part of the brain stem are the midbrain, the ring bump and the spinal cord , also known as the medulla oblongata.

2. Spinal cord

The spinal cord has the fundamental mission of transporting nerve impulses from the brain to the 31 pairs of nerves of the peripheral nervous system.

There are two main ways in which information flows:

  • Afferent pathway: in which information circulates from the trunk, neck and four limbs to the brain.
  • Efferent pathway: signals travel from the brain to the rest of the body.

In addition, some of its other tasks involve the control of vegetative and immediate movements.

Peripheral Nervous System

The peripheral nervous system is responsible for transmitting the signals through the spinal and spinal nerves , which are outside the central nervous system but are intended to connect it with the rest of the structures and systems.

If we continue with the anatomical classification, the SNP is composed of cranial and spinal nerves.

3. Cranial nerves

Cranial nerves are composed of 12 pairs of nerves, hence they are also known as cranial pairs. They originate in the brain and at the level of the brain stem, and are distributed throughout the body through holes located at the base of the skull, in the neck, chest and abdomen.

These nerves are born located according to the work they will perform. Those in charge of transmitting motor information travel along the efferent pathway , and have their origin in the brain stem.

While the fibers responsible for the sensory and sensory signals, which cross the afferent pathway, are born outside the brain stem.

4. Spinal nerves

The spinal nerves, or spinal nerves, are 31 pairs of nerves that are responsible for transmitting sensory signals, such as touch or pain, from the trunk and the four extremities to the central nervous system . In addition, they mediate information from the posture, muscles and joints, thus taking the information from the SCN to the rest of the body.

There is another classification of the peripheral nervous system according to the function of each of its pathways; separating between the somatic nervous system , responsible for intermediating between the internal organism and the external environment; and the autonomic or vegetative nervous system, which mediates the connections and internal communication of the body.