Autonomic Nervous System
definition
The human nervous system can be divided in several ways:
The first classification is based on where the respective parts of the nervous system are:
- A distinction is made between a central nervous system (CNS), which consists of the brain and the spinal cord,
- and a peripheral nervous system (PNS), which includes all other nerves, just the peripheral ones.
The other classification depends on whether the consciousness is involved or not:
- The somatic nervous system forms the arbitrary part. It can be from humans influenced and controlled is used, for example, to plan, carry out and coordinate movements with one another.
- The autonomic nervous system In contrast, (VNS) is not subject to our arbitrary control. It is therefore also called the “autonomous nervous system” because it practically works “by itself”.
The function of the autonomic nervous system
The vegetative nervous system sometimes fulfills many in our body vital tasks
- Breathing,
- Digestion,
- Blood pressure,
- metabolism
- and other organs.
The Operationsthat happen here all the time are usually cooked to us unaware. You don't have to actively think about the fact that you have to keep breathing and the intestine digests our food even without us being constantly aware of it and practically giving it the command to do so.
On sudden changes (for example on a full stomach or on a lion standing in front of you at once), the autonomic nervous system can react very quickly and the Adjusting the functions of the body (So either stimulation of digestion or general activation, which enables one to run away).
This is much faster possible, as if hormones for such reactions would be responsible, as this is first poured out and then via Bloodstream need to be transported to their target organs.
Since there are so many parallel events in our body, for the most part very complex processes it is only an advantage for us that the vegetative nervous system in healthy people unconsciously always ensures that they are correct. The Nerves of the autonomic nervous system end so in principle on the smooth muscle cells. These are located in almost all internal organs and are not subject to voluntary motor skills. Of course, the autonomic nervous system is also subject to one control. This is done using superordinate centers of the brain and about hormones.
Classification of the autonomic nervous system
The vegetative nervous system is divided into three parts:
- First of all, there are the opponents Sympathetic
- and Parasympathetic nervous system
- and then there is the nervous system of the viscera, also: enteric nervous system (ENS).
The enteric nervous system consists of one Nerve plexus, the between the individual layers of hollow organs is embedded. These include:
- Heart,
- Bladder,
- Gastrointestinal tract and the
- uterus.
The digestive organs are once again an exception, as this nervous system works completely independently of the central nervous system and its functioning can only be more or less modulated via the sympathetic or parasympathetic nervous system.
The Sympathetic is the part of the autonomic nervous system that has most Systems starts up and the Body more attentive and efficient makes. In English one describes one's main tasks as "Fight and flight". So it enables us to fight and / or to flee.
So some examples of sympathetic responses are:
- Expansion of the Pupils (you can see better),
- faster and stronger Heartbeat (a lot of blood has to be pumped? into the muscles in order to be able to run away if necessary or into the brain and think well),
- sweat,
- advanced respiratory tract (you should be able to breathe deeply in order to supply the blood with sufficient oxygen),
- Shutting down the digestion (After all, there are more important things at the moment) and
- Tension of the Sphincters (since it would be rather bad at such moments if the contents of the bladder were to empty).
The Parasympathetic nervous system is responsible for the opposing processes. This part of the vegetative nervous system takes care of the Body functions at rest. One describes one's tasks as "Rest and digest". When the parasympathetic part of the nervous system predominates, the body is in a state of rest, one is able to recover and digest.
According to the examples listed above, this means:
- The Pupils get tight,
- the heart beats slower and with less pressure,
- the respiratory tract get closer,
- the digestion is stimulated and
- the Sphincters relax.
- The the only exception put the Sweat glands that are not influenced at all by the parasympathetic nervous system.
Although the tasks of the sympathetic and parasympathetic nervous system are so fundamentally different, one can do theirs Nerve fibers in the body cannot be distinguished with the naked eye.
They both arise from the central nervous system and pull to the organ musclesr.
