• What is the nervous system?
• parts of the nervous system
• nervous system functions
• nervous system diseases

We explain what the nervous system is and what its functions are. Parts of the nervous system and most common diseases.

The first neuron is believed to have appeared 635 million years ago.

What is the nervous system?

The nervous system is called the set of organs and structures of control and information of the human body, constituted by cells highly differentiated known as neurons, which are capable of transmitting electrical impulses along a vast network of nerve endings.

The nervous system is common to human being and most chordate animals, arthropods, molluscs, flatworms and cnidarians. Other animal groups, such as the protozoa, the porifera and the floorsOn the other hand, they do not have a differentiated nervous system.

This transmission device chemical energy Y electrical runs through the entire body and allows coordination of the movements and actions of the body, both conscious and reflex, from which two types of nervous system are distinguished: the somatic and the autonomous. The former would deal with the connection between the extremities of the body and the brain, while the latter deals with reflex and involuntary actions.

Studies on the evolution of the nervous system indicate that the edge of the sponges, despite not having nerve cells, showed the genetic bases for the appearance of this system. It is believed that the first neuron appeared 635 million years ago, in the Ediacaran period, and its evolution would run parallel to the development of the eyes and other complex senses in primitive animals.

parts of the nervous system

The nervous system of the human body is divided into two sets:

• Central Nervous System (CNS). Responsible for processing the information collected by the senses and taking conscious actions. It is made up of the following bodies:
  • the encephalon Its most voluminous part, which encompasses the brain, divided into its two hemispheres; the cerebellum, which integrates motor functions and is in the region of the neck; and the brain stem that connects the spinal cord to the brain, composed of the midbrain, pons, and medulla oblongata.
  • Spinal cord. Extension of the brain that goes inside the bones of the spinal column and to which all the nerve endings of the body are connected.
• Peripheral Nervous System (PNS). The peripheral nervous system is made up of nerves, which run through the body and are divided into two groups:
  • Cranial nerves. There are 12 pairs of nerves located, as their name indicates, in the head, where they control information pertaining to the face, neck and main senses, connecting everything to the brain.
  • spinal nerves. There are 31 pairs of nerves that control information from the trunk and extremities, connecting to the spinal cord.

nervous system functions

As stated before, the nervous system has the basic function of connecting nerve processing centers such as the brain, with the periphery of the extremities and the various organs of the body.

In the first place, this allows the muscles to be activated and promote movement, both voluntary (walking, holding things, etc.) and involuntary (bowel movements, breathing, reflections, etc.). Second, it allows coordination sensory input of stimuli, such as pain and touch, and their transmission to elicit responses, which is vital in protecting the organism like an everything.

nervous system diseases

Alzheimer's affects areas of the brain linked to memory.

The best known of the diseases that afflict the nervous system are:

• Encephalitis. This is the name given to the presence of foreign bodies in the brain, such as virus either bacteria. Infections in this place are very delicate, since any damage to the brain can result in loss or decrease in its functions.
• Epilepsy. This congenital disease is due to an excessive activation of certain corners of the brain, which respond to external stimuli in a disorderly manner and generate seizures, lack of coordination and slowness.
• Sclerosis. Differentiated between multiple and lateral, it is a series of congenital disorders in which neurons lose their myelin, a layer that covers them and guarantees the effective transmission of information. This translates into loss of the capacity for voluntary movement and even perceptual alterations.
• Alzheimer's disease. This is the most common form of senile dementia, which affects areas of the brain linked to memory recent and the language, producing progressive deterioration of cognitive functions, preventing speaking, writing, read, or simply recognize the immediate reality. It starts after the age of 60 and at the moment there is no cure.
• Parkinson disease. It is a congenital disease that causes a decrease in dopamine in the nervous system, preventing nerve coordination and generating involuntary movements, as well as sleep disorders, depression and difficulties in chewing, speak or swallow