Nervous system and principles of apparatus operation

The art of medicine appeared not as the fruit of theoretical reasoning but,
on the contrary, people started thinking about theoretical
reasoning when methods of treatment had been already found
A. Celsus, III-II B.C.

A disease, in fact, is informational disorder at different levels of
organization of physiologic systems, whereas maintaining life
and health is, in fact, the controlled balance
G.G.Gvidott, 1990

The nervous system ensures adaptation of the body to the external environment. Under the constantly changing conditions throughout our lives the nervous system regulates the activity of all tissues and organs, interconnects organs and parts of the body, and enables a dialogue, or feedback of the body's needs relative to the external environment (homeostatic and behavioural activity).

This subsystem unites the body into an integral system. All of its multiple functions are performed by 40-45 billion nerve cells - neurons. That is why the name of DENAS devices includes the "neuro" component, which means, for DENAS, "operating with and acting as part of the nervous system".

Neurons possess the following unique abilities:

  • become excited (active state) under the effect of physical or chemical stimulii;
  • accept, cipher and process information about the state of the external and internal environment of the body;
  • transfer information in the form of electric pulses (and by other means) to other nerve cells or organs (muscles, glands, vessels, etc.) by establishing the link between them;
  • store a copy of information in their memory: the ability of nerve cells to store information allows the frontal lobe of the human brain to store in memory everything which has taken place in one's entire life. The capacity of this memory is such that it could contain all genetic memory of one's ancestors.

Nerve cells are of different forms and sizes (from 5 to 10 microns). Each neuron has short structures (dendrites) and long processes (axons) (Fig. 1). Dendrites receive information from other nerve cells. The number of short processes of each neuron may vary from 1 to 1,500. The axon serves to transfer the output of the processed information: in one case, from receptor structures of nerve cells of the skin, inner organs and tissues to the central nervous systems, and in other cases, from the central nervous systems to organs, tissues and skin. This explains why the long processes of nerve cells are called pathways. As a rule, one neuron is connected with a large number of other nerve cells, which ensures their interaction and the possibility of formation of complex structures, regulating various functions



Anatomical structure of a neuron
fig.1

A complex group of neurons which regulates any specific function form a nerve centre (for example, vasomotor centre, centre of speech, respiratory centre, etc.). The organisation of the nerve centre is structured around a group of neurons, forming the nucleus centre. In a number of cases, due to the fact that the length of the processes may reach 1-1.5 m, neurons are united in a single functional group even though they may be distributed around different anatomic zones.

The major class of neurons, the nerve centres and nucleii are located in the brain and spinal cord. Hence the latter are distinguished as the central nervous system.

The brain is located in the cavity of the skull and is surrounded by three membranes which protect it against damage. The brain regulates hormones, immunity, cardiac activity, blood pressure, breathing, temperature, positioning of the body (balance, etc), motor activity, food and liquid requirements, reflex interaction of the body and environment, internal state of the body (homeostasis), mental activity, training and memory, emotions and speech, behavioural reactions, thinking, sleep and sleeplessness, consciousness and awareness, etc.

The spinal cord is located in the cavity of the spine, and is is surrounded by three sheaths and strengthened by ligaments. It starts from the upper edge of the cranial vertebra and continues down to the 1-2 lumbar vertebra. With the help of nerve cell complexes, the spinal cord is connected with the brain. The connections between the spinal cord (and therefore the brain) and the skin, motor apparatus and inner organs are also effected with the help of processes of nerve cells. From the outlet points of the spinal cord and brain, these are interlaced, forming radices, nerve plexuses, nerve trunks and spinal nerves (Figs 2-4). The set of these nerve formations and their multiple branches forms the peripheral nervous system.



Cross-section of the spine   A spinal cord segment   A scheme of spinal radices and nerves projection onto the spinal column
fig.2   fig.3   fig.4

Depending on their functions, all nerve cells may be divided into three groups:

  1. those which import information signals from receptors of sensation organs (sensor systems of the body) to the brain and spinal cord. These are called sensitive or afferent;
  2. those which transfer information from the brain and spinal cord to all organs and tissues (executors). They are called motor or efferent;
  3. those which serve to interconnect neurons of the brain and spinal cord. Called intercalary neurons (interneurons), these cells form the most numerous group of nerve cells and differ significantly in form and function.

Receptors are at the ends of the processes of sensitive nerve cells in the body, and are adapted for the acceptance of certain stimulii from the external or internal environment. They also are adapted for the conversion of its physical or chemical energy into nerve excitation. All receptors which accept stimulii (signals) from the external environment are classed as exteroreceptors; those accepting stimulii from muscles, tendons, joints and ligaments are propri-oreceptors; those receiving messages from inner organs are classed as interoreceptors. In the sensor system, signals are coded (ciphered) by the binary code, i.e. by the presence or absence of an electric pulse in a certain period of time. Such method of coding is extremely simple and stable, resisting interference. Information about the stimulus and its parameters is transferred in the form of single pulses as well in the form of groups, batches of pulses. The amplitude, duration and shape of each pulse are similar but the number of pulses in a batch, their repetition rate, duration of batches and intervals between them, as well as the time pattern of the batch, differs and depends on characteristics of the stimulus. The sensor information is also coded by the number of simultaneously excited neurons and by their location in the neuron layer. As distinct from telephone and television codes which are decoded by restoration of the initial form of a message, in the sensor system such decoding does not take place. The entire nervous system by convention is divided into two main sections - somatic sensor (animal) and vegetative (visceral). The somatic sensor nervous system provides the skin and sensation organs with sensitive nerves, and is responsible for the functions of the support-motor apparatus (bones, joints, muscles). The vegetative nervous systems is responsible for regulation of functioning of the cardiovascular system, respiratory organs, digestive apparatus, endocrine glands and urogenital organs, and also controls feeding of muscles (Fig. 5). As with the somatic sensor, the vegetative nervous system has its representation in the brain and spinal cord (central section) in addition to the peripheral, or out-of-brain section (ganglions, nerve trunks and nerves going to inner organs). The vegetative nervous system is then divided into two parts: sympathetic nervous system and parasympathetic nervous system.

Brain, spinal cord and vegetative nervous system
fig.5

Sympathetic-parasympathetic duality, by which either stimulation or cessation of working organs is induced, contributes to the preservation of the dynamic balance of certain corresponding functions (see Table 4).

Parasympathetic stimulation causes an inhibiting action in some organs, and the stimulation effect in others. In addition, sometimes the sympathetic system acts as a stimulator and sometimes an inhibitor. Though often sympathetic activation causes a change in functioning of the corresponding organ that is opposite to the effect of parasympathetic activation, it is not correct to view the interconnection of two sections of the vegetative nervous system as conflicting. On the contrary, together they ensure the complete adaptation of the body to the changing conditions of the environment, i.e. in the final analysis, they collaborate in synergy.



Table 4
Responses of Organs at Stimulation of Sympathetic and Parasympathetic nerves
(Tabeev D.M., 2001, pp 92-93)

Organs Parasympathetic system Sympathetic system
Heart
frequency
heartbeat force
conductivity
Vessels
skin
muscles
peritoneo-pelvic organs
inner organs
coronary
lung
brain
salivary glands
external genital organs

inhibition
-
-

-
-
dilatation

constriction
-
dilatation
-
-

stimulation
-
-

constriction
dilatation
constriction

dilatation
-
constriction
-
-
Flat muscles
esophagus
cardia
stomach

pylorus
bowels

rectum
sphincter muscle of anus
urinary bladder (detrusor)
cystic sphincter
ureter
bronchus
iris
ciliary muscles
pilomotor muscles
third eyelid
penis
uterus


gravid uterus
non-qravid uterus

contraction
dilatation
relaxation
tonus and peristaltic
increase
relaxation
tonus and peristaltic
contraction
increase
contraction
increase
contraction
constriction
constriction
contraction
-
-
erection
varies depending on type
of living and functional
state
-
-

increase
contraction
tonus and peristaltic
decrease
contraction
tonus and peristaltic
decrease
relaxation
contraction
relaxation
-
dilatation
-
-
relaxation
-
-
ejaculation
varies depending on type
of living and functional
state
contraction
relaxation
Glands
salivary
nasal
gastric
pancreatic
sudoriferous
islets of Langerhans
brain layer of epinephros
lever
main metabolism

stimulation
-
-
-
-
stimulation
-
-
-

stimulation
inhibition
-
-
stimulation
-
-
glycogenolysis
improvement

Utilising the nerves and humoral pathways, the vegetative nervous system coordinates and adapts the activities of all organs. It also participates in the preservation of the dynamic balance of life functions.

It seems that ancient eastern ideas about the balance of the body derived from the harmony of two opposite phenomena apparently can be considered as the dynamic stability of homeostasis of the body - made possible by the functions of the vegetative nervous system (D.M. Tabaeva, 2001).

The functions of the somatic sensory, sympathetic and parasympa-thetic components of the vegetative nervous system are effected with the aid of the complex reflex actions. These focus on the body's self-regulation of the stability of the internal environment.

Reflex, the response of the body to any stimulus, is a separate functional task of the nervous system. The simplest representation of this function is "stimulus -> response". However, as far as the human being is concerned, reflex activity is the result of very complex processing of information. For there to be an expected and successful response to the stimulus, retaining control over the result of this response is necessary. This control is effected by a system which, once the organ or muscle (effector) has completed the initial command, transfers information concerning the result from the organ back to the nerve or node acting as the command centre. The command centre is thus informed as to whether,according to the body's internal environment, the response has been effective and as expected. Receptors, then, accept not only the initial command stimulus but also the response to this stimulus. Availability of such control turns the reflex arch into the reflex ring via which nerve pulses are permanently circulating (direct link and feedback). This constant monitoring during the life of the stimulus/response cycle provides a mechanism for measuring responses, registering abnormalities, making adjustments, remeasuring the response, and so on. According to experimental data, during just 1 second, nerve cells perform 100 trillion elementary operations, while modern computers are capable of making only one billion.

Due to the constant, almost instantaneous receiving and processing of external (e.g. environmental) and internal (i.e from organs and tissues) information, in each single second the nervous system can regulate (e.g. by increasing/decreasing the activity of) all organs and systems in the body, thereby aiming to maintain optimum system stability.

For example, in the case of an increase in the body temperature due to external (hot weather) or internal (infection) reasons, a normally functioning body will not overheat. The temperature of the body is regulated by neural feedback mechanisms which operate primarily through the hypothalmus (which contains not only the control mechanisms, but also the key temperature sensors.)

The mechanism of this self-regulating phenomenon is summarised as follows:

  1. interoreceptors register an increase in the internal temperature beyond the safe level for the human body;
  2. electric pulses sent via afferent paths transmit this information to the central nervous system (Fig. 7);
  3. there it is analyzed, a decision reached and the command for implementing this decision is transferred to the executive section of the brain (see Fig. 6);
  4. via efferent conducting paths, electric pulses from the brain send the solution to the organ executors;
  5. after receiving the command, skin blood vessels are dilated, and at almost exactly 37 degrees sudoriferous glands begin functioning (Fig. 8);
  6. as a result, the skin operates as a radiator by losing heat from the expanded vessels to the environment;
  7. sudoriferous glands produce abundant sweat, and evaporation, as known by the lays of physics, increases the heat transfer;
  8. by these means, the high temperature is decreased and normalization of the body's internal environment is restored;
  9. feedback (back afferentation) to the central nervous system of the adjusted condition has been occurring throughout the remedial process, until finally the measured temperature is comparable with the standard, and the intense functioning of efferents (blood vessels and sudoriferous glands) ceases (Fig. 9).



Functional system, including homeostatic and behavioral (cognitive) links of self-regulation (after K.V. Sudakov, 1990)   A scheme of homeostasis self-regulation in body temperature increase. Primary afferentation:   A scheme of homeostasis self-regulation in body temperature increase. Efferentation:   A scheme of homeostasis self-regulation in body temperature increase. Backwards afferentation of achieved useful result:
fig.6   fig.7   fig.8   fig.9

Should excessive or permanent stress, or any pathological state or desynchronising disease be experienced, malfunctioning of the nervous system can occur. Consequently, faulty regulatory systems of certain of the body's reflex mechanisms cannot ensure optimal functioning of organs and systems of organs. The person may suffer from feeling constantly unwell, and frequent acute diseases may develop, with chronization of diseases and metabolism derangement commonplace.

Under these conditions the use of the unique signal (with batched pulses) of the DENS/DENAS-therapy apparatuses (which operation is based on the principle of the "biological" feedback) leads to the recovery of the regulatory abilities of the nervous system, and typically, a high rate of recovery.

For example, a disturbance of nerve regulation in children can cause an increase in body temperature due to distortion of the information flow - and dilatation of peripheral blood vessels and activation of functioning of sudoriferous glands does not occur. The essential cooling mechanism fails. As a result, the skin of such patients is pale and cold, their sickness worsens significantly to the point of vomiting, and delirium, algospasm and loss of consciousness can occur. If under these conditions you apply electrodes of the DENAS apparatus to a certain skin zone, the neuron-like signal will reach the central nervous system via its conduits, and form the appropriate response. Following this the command (signal) required for normalisation of the body's internal environment will go to the organ executors, resulting in correction of body temperature and improvement of the patient's condition (Fig. 10).



An approximate scheme of DENS-therapy apparatus operation
fig.10

In a similar way, the application of DENS/DENAS-therapy apparatuses on certain other biologic energy informational zones, with influence on the receptor system of the skin typically leads to elimination of other functional disorders of the body.