The “Х” receptor, afferent channels, analyzer-informant (activator of action) and efferent channels (stimulator) comprise the control block. The receptor and afferent channels represent direct positive communication (DPC). It is direct because inside SFU the guiding signal (information on the presence of external influence) goes in the same direction as the external influence itself. It is positive because if there is a signal there is a reaction, if there is no signal, there is no reaction. Thus, the SFU control block reacts to the external influence. It can feel and detect/segregate specific signal of external influence from the multitude of other external influences and depending on the presence or absence of specific signal it may decide whether or not it should undertake its own action. Its own action is the inducement (stimulation) of the executive elements to operate. There exist uncontrollable and controllable SFU. The control block of uncontrollable SFU decides whether or not it should act, and it would make such decision only depending on the presence of the external influence. The control block of controllable SFU would also decide whether or not it should act depending on the presence of the external signal and in the presence of additional condition as well, i.e. the permission to perform this action which is communicated to its command entry point. The uncontrollable SFU has one entry point for the external influence and one outlet /exit point/ for the result of action. The logic of work of such SFU is extremely simple: it would act if there is certain external influence (result of action), and no result of action is produced in the absence of external influence. For uncontrollable SFU the action regulator is the external influence itself. It has its own management which function is performed by the internal control block. But external management with such SFU is impossible. It would “decide” on its own whether or not it should act. That is why it is called uncontrollable. This decision would only depend on the presence of external influence. In the presence of external influence it would function and no external decision (not the influence) can change the internal decision of this SFU. The uncontrollable SFU is independent of external decisions. It will perform the action once it “made a decision”. The example of uncontrollable SFU is, for instance, the nitroglycerine molecule (SFU for micro-explosion). If it is shaken (external influence is shaking) it will start to disintegrate, thereby releasing energy, and during this process nothing would stop its disintegration. The analogues of uncontrollable SFU in a living organism are sarcomeres, ligands of haemoglobin, etc. Once sarcomere starts to reduce, it would not stop until the reduction is finished. Once the ligand of haemoglobin starts capturing oxygen, it would not stop until the capturing process is finished. Unlike uncontrollable SFU, the controllable SFU have two entry points (one for the entry of external influence and another one for the entry of the command to the analyzer) and one outlet/exit point/ for the result of action. The logic of work of controllable SFU is slightly different from that of the uncontrollable SFU. Such SFU will produce the result of action not only depending on the presence of the external influence, but the presence of permission at the command entry point. Implementation of action will start in the presence of certain external influence and permission at the command entry point. The action would not be performed in the presence of the external influence and the absence of permission at the command entry point. For the controllable SFU the action regulator is the permission at the command entry point. That is why suchSFU are called controllable. The analogues of controllable SFU in a living organism are, for example, pulmonary functional ventilation units (FVU) or functional perfusion units (FPU), histic functional perfusion units (FPU), secretion functional units (cells of various secretion glands, SFU), kidney nephrons, liver acinuses, etc. The control block’s elements are built of (assembled from) other ordinary elements suitable in terms of their characteristics. It can be built both of executive elements combined in a certain manner and simultaneously performing the function of both execution and management, and from other executive elements not belonging to the given group and segregated in a separate chain of management. In the latter case they may be precisely the same as executive elements, but may be made of other elements as well. For example, muscular contraction functional units consist of muscular cells, but are managed by nervous centers consisting of nerve cells. At the same time, all kinds of cells, both nerve and muscular, are built of almost identical building materials – proteins, fats, carbohydratesand minerals. The difference between the controllable and uncontrollable FSU is only in the availability of command entry point. It is it that determines the change of the algorithm of its work. Performance of the controllable SFU depends not only on the external influence, but on the M disabling at the command entry point. The control block is very simple, if it contains only DPC (the “Х” receptor and afferent channels), the analyzer-informantand a stimulator. SFU are primary cells, executive elements of any systems. As we can see, despite their elementary character, they represent a fairly complex and multi-component object. Each of them contains not less than two types of elements (management/control and executive) and each type includes more and more, but these elements are mandatoryattributes of any SFU. The SFU complexity is the complexity of hierarchy of their elements. There is no any special difference between the executive elements and the elements of management/control. Ultimately all in this world consists of electrons, protons and neutrons. The difference between them lies only in their position in the hierarchy of systems, i.e. in their positional relationship. The composite SFU contains 4 simple SFU. In the absence of the external influence all simple SFU are inactive and no resultof action is produced. In the presence of the external influence of “Х”, if the command says “no” (disabling of /ban on action), all SFU would be inactive and no result of action produced. In the presence of external influence and if the command says “yes” (permission for action), all SFU would be active and the result of action produced. The “capacity” of the composite SFU is 4 times higher than the “capacity” of simple SFU. SFU is activated through the inputs of command of their control blocks. Every simple SFU has its own DPC and DPC common for all of them. Uncontrollable and controllable SFU may be used to build other (composite) SFU, more powerful than single SFU. In the real world there are few simple SFU which bring about minimal indivisible result of action. There are a lot more of composite SFU. For instance, the cartridge filled with grains of gunpowder is a constituent part of SFU (SFU for a shot), but its explosion energy is much higher that that of single grain of gunpowder. The composite SFU flow diagram is very similar to that of simple SFU. It is only quantity variance that stipulates the difference between the composite and simple SFU. Simple SFU contains only one SFU, just SFU itself, whereas the composite SFU contains several SFU,sothere is a possibility of strengthening of the result of action. Thus, simple and composite SFU contain two types of elements: executive elements (effectors performing specific actions for the achievement of the system’s preset ovearll goal) and the elements of management (block) (DPC, the analyzer-informant and the stimulator activating SFU). Composite SFU has the same control block as the separate SFU, i.e. the elementary one with direct positive (guiding) connection (DPC). Composite SFU perform based on the “all-or-none” principle, too, i.e. they either produce maximal result of action in response to external influence or wait for this external influence and do not perform any actions. Composite SFU only differ from simple SFU in the force or amplitude of reaction which is proportionalto the number of simple SFU. If the domino dices are placed in a sequential row the result of their action would be the lasting sound of the falling dices which duration would be equal to the sum of series of drops of every dice (extension of duration of the result of action). If the domino dices are placed in a parallel row the result of their action would be the short, but loud sound equal to the total sound volume resulting from the drop of each separate dice(capacity extension). The performance cycle of an ideal simple and composite SFU is formed by micro cycles: perception and selection of external influence by the “X” receptor and decision-making; influence on the executive elements (SFU); response/operation of executive elements (SFU); function termination. The “X” receptor starts to operate following the onset of external influence (the 1st micro cycle). Subsequently some time would be spent for the decision-making, since this decision itself is the result of action of certain SFU comprising the control block (the 2nd micro cycle). Thereafter all SFU would be activated (joined in) (the 3rd micro cycle). The operating time of the SFU response/operation depends on the speed of utilization of energy spent for the SFU performance, for example, the speed of reduction of sarcomere in a muscular cell which is determined by speed of biochemical reactions in the muscular cell. After that all SFU terminate their function (the 4th micro cycle). At that, the SFU spends its entire energy it had and could use to perform this action. As far as the sequence of actions and result of action would always be the same, the measure of energy would always be the same as well (energy quantum). In order for the SFU to be able to perform a new action it needs to be “recharged”. It may also take some time (the time of charging). The way it happens is discussed in the section devoted to passive and active systems (see below). Any SFU’s performance cycle consists of these micro cycles. Therefore, its operating cycle time would always be the same and equal to the sum of these micro cycles. Once SFU started its actions, it would not stop until it has accomplished its full cycle. This is the reason of uncontrollability of any SFU in the course of their performance (absolute adiaphoria), whereby the external influence may quickly finish and resume, but it would not stop and reactto the new external influence until the SFU has finished its performance. In real composite SFU these micro cycles may be supplemented by micro cycles caused by imperfection of real objects, for example, non-synchronism of the executive elements’ operationdue to their dissimilarity. Hence, it follows that even the elementary systems represented by SFU do not react/operate immediately and they need some time to produce the result of action. It is this fact that explains the inertness/lag effect/ of systems which can be measured by using the time constant parameter. But generally speaking it is not inertness/lag effect/, but rater a transitory (intermittent) inertness of an object (adiaphoria), its inability to respond to the external influence at certain phases of its performance. True inertness is explained by independence of the result of action of the system which produced this result (see below). Time constant is the time between the onset of external influence and readiness for a new external influence after the achievement of the resultof action. The analogues of composite SFU are all objects which operate similarly to avalanche. The “domino principle” works in such cases. One impact brings about the downfall of the whole. However, the number of downfalls would be equal to the number of SFU. Pushing one domino dice will cause its drop resulting just in one click. Pushing a row of domino dices will result in as many clicks as is the number of dices in the row. Biological analogues of composite SFU are, for example, functional ventilation units (FVU), each of which consisting of large group (several hundred) of alveoli which are simultaneously joining in process of ventilation or escape from it. Liver acynuses, vascular segments of mesentery, pulmonary vascular functional units, etc., are the analogues of composite SFU. Thus, simple SFU is the object which can react to certain external influence, while the result of its performance would always be maximal because the control block would not control it, i.e. it works under the “all-or-none” law. The type of its reaction is caused by the type of SFU. There are two kinds of simple SFU: uncontrollable and controllable. Both react to the specific external influence. But additional external permission signal at the command entry point is required for the operation of controllable SFU, whereas the uncontrollable SFU have no command entry point. Therefore, the uncontrollable SFU does not depend on any external guiding signals. The control block of controllable and uncontrollable SFU consists of the analyzer-informant and has only DPC (the “Х” informant and afferent channels). The compositeSystemic Functional Unitis a kind of an object similar to simple SFU, but the result of its action is stronger. It works under the “all-or-none” law, too, and its reaction is stipulated by type and number of its SFU. It can really be that the constituent parts of composite SFU may be controllable and uncontrollable, and the difference between them may only be stipulated by the presence of command entry point in the general control block through which the permission for the performance of action is communicated. The control block of a system is elementary, too, and has onlyDPC and analyzer-informant. Hence, any SFU function under the “all-or-none” law. SFU is arranged in such a way that it either does nothing, or gives out a maximal result of action. Its elementary result of action is either delivered or not delivered. There might be SFU which delivers the result of action, for example, twice as large as the result of action of another SFU. But itwill always be twice as large. Each result of action of a simple SFU is quantum of action (indivisible portion), at that being maximal for the given SFU. It is indivisible because SFU cannot deliver part (for instance, half) of the result of action. And as far as it is “the indivisible portion” there can not be a gradation. For instance, SFU may be opened or closed, generate or not generate electric current, secrete or not secrete something, etc. But it cannot regulate the quantity of the result of action as its result always is either not delivered or is maximal. Such operating mode is very rough, inaccurate and unfavorable both for the SFU per se and its goal/objective. Let’s imagine that instead of a steering wheel in our car there will be a device which will right away maximally swerve to the right when we turn a steering wheel to the right or will maximally swerve to the left if we turn it to the left. Instead of smooth and accurate trimming to follow the designate course of movement the car will be harshly rushing about from right to left and other way round. The goal will not be achieved and the car will be destroyed. Basically the composite Systemic Functional Unit could have delivered graded result of action since it has several SFU which it could actuate in a variable sequence. But such system cannot do so because it “does not see” the result of action and cannot compare it with what should be done/what it should be.