The nervous system is a kind of apparatus that connects all organs, creates a relationship between their functions, thereby guaranteeing the smooth operation of the human body as a whole. The main element of this complex mechanism is the neuron - the smallest structure that exchanges impulses with other neurons.
The main vegetative processes in the body
The organization of the autonomic nervous system (ANS) is present not only in humans and vertebrates. The term “vegetative” was introduced by scientists, on the basis that this complex mechanism, consisting of chains of neurons, is also inherent in primitive organisms, regulating the elementary processes of their life.
The English physiologist called the autonomic nervous system autonomous, since its functions are not amenable to conscious control or termination. In mammals, which, in fact, includes humans, she is responsible for several vital biological processes:
- the work of the cardiovascular system;
- blood circulation regulation ;
- digestion, respiration;
- highlight functions;
- reproduction and metabolism.
Departments of the autonomic system: physiological characteristics
If we consider the autonomic system from an anatomical point of view, it can be conditionally divided into two subsystems: sympathetic (SNS) and parasympathetic (PNS). Their efferent pathways are based on the serial connection of neurons emanating from the central nervous system (CNS).
The anatomical differences between the sympathetic and parasympathetic nervous systems are in the arrangement of neural cell bodies - the belonging SNAs are located in the spinal cord of the thoracic and lumbar vertebrae, and those that belong to the PNS section are grouped in the medulla oblongata and sacral parts of the spinal cord. The second neural chain is located outside the central nervous system, it forms ganglia in close proximity to the spine.
The role of the metasympathetic department
The sympathetic and parasympathetic parts of the nervous system have a fundamental effect on the functioning of most internal organs through the so-called vagus nerve. If we compare the transmission speeds of the pulses of the central and vegetative systems, the latter is significantly inferior. The unifying SNS and PNS can be called the metasympathetic department - this site is located on the walls of organs. Thus, all internal processes of the human body are controlled thanks to the established work of vegetative structures.
The principle of the vegetative departments
The functions of the sympathetic and parasympathetic nervous system cannot be attributed interchangeably. Both departments supply the same tissues with neurons, creating an unbreakable bond with the central nervous system, but can have the exact opposite effect. The table below will help to make sure of this clearly:
Organs and systems | Sympathetic system | Parasympathetic system |
Pupils | expand | taper |
Salivary glands | causes a small amount of thick fluid | intensive production of watery secretions |
Lacrimal glands | does not affect | causes increased secretion |
Contractility of the heart muscle, rhythm | provokes palpitations, increases contractions | weakens, decreases heart rate |
Blood vessels and blood circulation | responsible for narrowing arteries and increasing blood pressure | almost no effect |
Respiratory organs | helps to strengthen, expand the lumen of the bronchi | narrows the lumen of the bronchi, respiratory depression occurs |
Musculature | tones | relaxes |
Sweat glands | activates sweat production | does not affect |
The work of the digestive tract and digestive organs | slows down mobility | activates mobility |
Sphincters | activates | slows down |
Adrenal glands and endocrine system | adrenaline and norepinephrine production | does not affect |
Genitals | responsible for ejaculation | responsible for erection |
Sympathicotonia - disorders of the sympathetic system
The sympathetic and parasympathetic parts of the nervous system are in an equal position, without one prevailing over the other. In other cases, sympathicotonia and vagotonia develop, which is manifested by increased excitability. If we are talking about the predominance of the sympathetic department over the parasympathetic, then the signs of pathology will be:
- fever;
- cardiopalmus;
- numbness and tingling in the tissues;
- irritability and apathy;
- increased appetite;
- thoughts of death;
- distraction;
- decreased salivation;
- headache.
Parasympathetic system disorder - vagotonia
If, against the background of weak activity of the sympathetic department, parasympathetic processes are activated, then the person will feel:
- excessive sweating;
- lowering blood pressure;
- change in heart rate;
- short-term loss of consciousness;
- increased salivation;
- fatigue
- indecision.
What is the difference between SNA and PNS?
The main difference between the sympathetic nervous system and the parasympathetic is its ability to increase the body's capabilities in the event of a sudden need. This department is a unique vegetative construction that, in an emergency, collects all available resources together and helps a person to cope with a task that is almost on the verge of its capabilities.
The functions of the sympathetic and parasympathetic nervous systems are aimed at maintaining the natural functioning of internal organs, even in situations critical for the body. The increased activity of the SNS and PNS helps to overcome various stressful circumstances:
- excessive physical activity;
- psycho-emotional disorders;
- complex diseases and inflammatory processes;
- metabolic disorders;
- the development of diabetes.
With mental upheaval in a person, the autonomic nervous system begins to work more actively. The sympathetic and parasympathetic departments enhance the action of neurons and strengthen the connection between nerve fibers. If the main objective of the PNS is to restore normal self-regulation and the protective functions of the body, then the effect of the SNS is aimed at improving adrenaline production by the adrenal glands. This hormonal substance helps a person cope with the suddenly increased load, it is easier to tolerate dramatic events. After the sympathetic and parasympathetic departments of the autonomic nervous system have used up all possible resources, the body will need rest. For a full recovery, a person will need 7-8 hours of night sleep.
Unlike the sympathetic nervous system, parasympathetic and metasympathetic autonomic departments have a slightly different purpose associated with maintaining the body's functions in peace. PNS acts differently, reducing the heart rate and the strength of muscle contractions. Thanks to the parasympathetic component of the autonomic system, digestion is stimulated, including when glucose is insufficient, protective reflexes (vomiting, sneezing, diarrhea, cough) are triggered, aimed at freeing the body from harmful and foreign elements.
What to do if there are violations from the autonomic system?
Having noticed the slightest disturbances in the functionality of the sympathetic and parasympathetic departments of the autonomic nervous system, you should consult a doctor. In advanced cases, violations lead to neurasthenia, gastrointestinal ulcers, hypertension. Medication should be prescribed only by a qualified neurologist, but the patient is required to eliminate any factors that excite the sympathetic and parasympathetic nervous system, including physical exertion, psycho-emotional shock, worries, fears and fears.
In order to establish vegetative processes in the body, it is advisable to take care of a cozy home atmosphere and receive only positive emotions. In addition to the above, physiotherapy, breathing exercises, yoga, and swimming should also be included. This helps to relieve general tone and relaxation.