The Central Nervous System is made up of the cerebrum (encephalon) and the spinal cord (the latter is shaped like a cylindrical tube and runs down the spinal canal from the first cervical to the first lumbar vertebra - but its lowermost nerve roots continue to the coccyx and form a bundle that resembles a horse's tail -).

The spinal cord transmits the information that descends from the brain to the rest of the body (output), and performs an inverse process receiving the information (input).

In turn, each part of the spinal cord is divided into segments: the metameres.

As an analogy, we could think of the spinal cord as a shoe with plugs, placed vertically: each plug would be a "metamere", from which a cable is born on each side (on the right and left).

Then from each plug, through its cables (nerve roots), electrical impulses are transmitted that are directed towards "different appliances" (muscles, organs, veins, arteries, etc.).

In the human body it is more complex, because also "these plugs" in addition to emitting electrical signals, receive them.

If more electricity began to circulate through a specific plug, we would be in the presence of a facilitated segment (it receives excessive stimuli from the “appliances” – perhaps the air conditioning is working too much -).

A facilitated segment is a highly excitable portion of the spinal cord that sends an abnormal amount of nerve impulses to the muscles, joints, or organs that depend on it.

Faced with a stimulus that seems weak, the "plug" is overloaded (for example: I bend down to look for a pin and I stay hard).

The objective of Osteopathy is to look for dysfunctions (loss of mobility) in the human body, and in this way generate a decrease in the overload of the nervous system.