subsystems respond in a nonlinear fashion (i.e., output disproportionate to input) to affect constancy or homeostasis of higher ordered systems that are critical for the expression of life.

Communication between these systems is complex, involving virtually every system in the body. Current scientific thought suggests, to a large degree, the body's responses are influenced by neuropeptides which 'flow freely' "...they transmit information throughout the brain and body in a network of communication, thereby integrating at the level of the whole organism" (Pert, 1990). These molecules interact with specific receptors to initiate specific actions. In this regard, human physiology, composed of various feedback loops or continuous cycles vacillating in sine waves, is partially consistent with Prigogine's model (Thibodeau & Patton, 1993). However, human physiology differs from Prigogine's model in the sense that subsystem response is predictable, not random as in inanimate systems. Moreover, communication between the organism at the cellular level is well known to involve changes in the cell membranes. Thus, the greater the level of cell membrane integrity, the greater is the likelihood of appropriate adaptive responses to environmental clues. Survival in animate forms is consequently linked to self-perpetuating systems that have an inherent intelligence.

Employing aspects of Panjabi's subsystem concept, Dr. Epstein developed a paradigm that relates the maintenance of spinal integrity of the whole organism to the interaction of communicating subsystems. His theories hold that new emerging properties and strategies can be developed for the nervous system to enhance the body's adaptive interactions with the ever changing environment. This line of reasoning also appears consistent with those views of evolution that suggest certain types of collective challenges to a species' survival may promote a saltatory jump in adaptation by that species (genetic drift). Such a dramatic response could, over a few generations, considerably alter the the species at several levels, such as physical appearance or altered physiology.

There is much evidence, such as genetic drift, that suggests that some creatures found on earth are already fully adapted to their environment. In a given species (humans or, even, butterflys) within certain individuals, there may be the ability to use sulfur instead of oxygen as the final electron acceptor. Bacteria living in the depths of swamps already do this; however, since they can also use oxygen, they do not recognize that they have this ability since the body does not live in a sulfur atmosphere, but rather an oxygen atmosphere. If there was a sudden loss of oxygen with a shift to sulfur, those creatures that could use sulfur would make the shift and become the procreators of the next generation. The others would likely die off. This is genetic drift; and it is recognized as the way that species evolve within their kind.

Spinal Integrity and Subsystem Interactions

Spinal and neural integrity is defined, herein, as that state in which the physical components and physiological processes of spine function are unimpaired, including the

Next Page