A conceptual model that describes a process involving five interactive, involuntary functions: (1). The inherent motility of the brain and spinal cord. (2). Fluctuation of the cerebrospinal fluid. (3). Mobility of the intracranial and intraspinal membranes. (4). Articular mobility of the cranial bones. (5). Mobility of the sacrum between the ilia (pelvic bones) that is interdependent with the motion at the sphenobasilar synchondrosis. This mechanism refers to the presumed inherent (primordial) driving mechanism of internal respiration as opposed to the cycle of diaphragmatic respiration (inhalation and exhalation). It further refers to the innate interconnected movement of every tissue and structure of the body. Optimal health promotes optimal function and the inherent function of this interdependent movement can be negatively altered by trauma, disease states or other pathology.