The research on the living systems are moving towards the knowledge on the relationships between the organism and its environment, by way of the information obtained in the fields of heredity, physical constitution, phenotypic adaptation. A biological subject possesses sensitivity (emotions), instincts, a capacity for learning (mind, intelligence) through which it is capable of acquiring understanding, knowledge, and consciousness of his reality. Through the processes involved in the physical structure and in the conscious and unconscious activities the organism actively participates in the specific mechanisms: equipped with a heredity they are intrinsic part of the life which unfolds within a chaotic physical and psychic environment.

In the complex system the “environment” has a function which favours creative activity and allows for evolutions of the dynamic system leading towards an individual “ecological dimension” in the man-nature-cosmos relationship. This is the role of the “environmental” parameter which connects the individual to nature's cosmic life, within the surrounding universe.

In the complex system individual “diversity” derives from the genetic program, from the casuality of the chaotic energetic dynamics and from the “environment” dominating his intra and extra psycho-physical life and at the origin of the chaotic movements.

These activities, characteristic of the complex dynamic system, collaborate in the “creation” of the affective and cognitive world, within which the individual achieves self-consciousness, becomes aware of the Self and of his own personal “identity”. The phenomenal consciousness leads him to share this identity with the “other”. The immune system has a role inside the system’s dynamics:it mediates the activities of the “internal and external environment” by acting as a communicational system of the information transmitted by the “environment” itself.

The immune system's (IS) function consists in coordinating the interior and exterior “environmental experiences” in relation to the casual dynamics occurring within the metabolic systems and subsystems: physical, psychic, sensorial, affective or mental. The immune system brings equilibrium along the Tao, the “passage” through the “middle road” which leads towards a stable equilibrium. The Tao is a science and rule of life; both are fundamental qualities for the harmonization of the complex system’s functional activities. The IS has been delegated to address, in a coordinated manner, the incalculable situations of “instability” created within the internal and external environment. Even the most remote part of the organism must be in constant communication, at local and at general levels, in order to provide the process of coordination necessary for the integration of the countless activities that all appear different; the “wisdom of the body” and the endless number of mental functions ensure the dynamic equilibrium upon which depends the stability of the system.

Because of the complexity of its activities and functions the IS is extremely chaotic; and possesses an extremely complex and delicate homeostatic mechanism which operates in a state of dynamic equilibrium among contrasting forces (emotions-brain; internal-external environment).

The interaction between matter, energy and information takes place in a complex environment. The structural coupling, the interaction of the organism-environment, give way to chaotic perturbations, which are the consequence of the phenomenological complexity due to barriers, events, contingencies and structures with interconnected functions.

Intricate and unpredictable correlations among the metabolic systems, at various levels, require an organization capable of managing the interaction between the complex system and the internal-external environment, inside which operate the energetic dynamics. Under these conditions it manifests itself with differentiated aspects due to the chaotic dynamics.

Here is revealed the existence of a dynamic order with an organization based on the simplicity of the process of “self-regulation”. This activity is made possible by the “adaptability” of the complex system.

The process of self-regulation allows for the constant maintenance of some regularity and order in the sequences of the biological structure, with virtual or real chaotic dynamics.The complex system'slinear and chaotic dynamics pertain to the individual's embryogenic evolution. With the increase of inter-connexions and ramifications inside the EC network there is an increase in the complexity of the chaotic systems: nevertheless they can be “regulated” by minimal movements of the controlling parameters. The complexity typical to the “circularity” inside the complex system and the environment, create difficulty for the environment’s integration into the complex dynamic system. The genetic patrimony supplies complex biological instructions, which pass from generation to generation, in order to maintain life and respect the “identity” of the cells, tissues, organs and functions; together these constitute the “biological identity” of the species, its codification and the preservation of the DNA's replication cycles.

In this manner and on the basis of the “laws of disorder” of deterministic chaos, a process of self-regulation is created. The self-regulation serves to compensate for the perturbations acting upon the environment.

A movement manifesting continuous alterations in the chaotic dynamics would normally provoke a structural change inside the system. The self-regulatory system’s “plasticity” helps to avoid these structural consequences. Changes of “state” compensate for the consequences of the disturbances provoked by the environmental dynamics. The “state” of the metabolic system, in relation to the environment, takes place when it assumes fractal, chaotic dynamics.