Physiology definition

Patterson GM, Wilson S, Whang JL, et al. Physiologic definitions of obUterative bronchiolitis in heart-lung and double lung transplantation a comparison of the forced expiratory flow between 25% and 75% of the forced vital capacity and forced expiratory volume in one second. J Heart Lung Transplant 1996 15 175-181. 

A major difficulty which has been encountered with these definitions (identified as a particular problem by EDSTAC) is the definition of the term adverse . For a chemical to be judged an ED, it is important to show that the response seen has an adverse effect on the health or reproductive capacity of affected organisms or populations and is not just a change which falls within the normal range of physiological variation. 

A commonly expressed definition is Thermal Comfort is that condition of mind that expresses satisfaction with the thermal environment. The definition implies that the judgment of comfort is a mental process that results from physical, physiological, and psychological factors and processes. Dissatisfac tion can lead to complaints and other undesirable side effects. 

To operate at a fixed definite vapour pressure is also an obvious impossibility, since this would involve a large range of temperature sufficient to cause physiological complications. 

In human exercise physiology, fatigue is often defined as an inability of a muscle or a group of muscles to sustain the required or expected force (Edwards, 1981). This definition is very applicable for the study of factors limiting dynamic or isometric exercise in intact organisms at varying intensities. 

Sepsis is a continuum of physiologic stages characterized by infection, systemic inflammation, and hypoperfusion with widespread tissue injury.1 The American College of Chest Physicians and the Society of Critical Care Medicine developed definitions to utilize for sepsis (Table 79—l).2 They provide physiologic parameters categorizing patients as having bacteremia, infection, systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, septic shock, or multiple-organ-dysfunction syndrome (MODS).2 Standardized definitions have been developed for infections in critically ill patients.3... 

Although the definition of allelopathy Includes stimulation as well as Inhibition of growth by allelochemicals (1., 4), allelochemicals that definitively affect mineral absorption by plant roots have been found to primarily Inhibit, rather than stimulate, the process. The first part of this review presents evidence that alteration of mineral absorption Is a physiological mechanism of allelopathy. Possible physiological and biochemical bases for the Inhibition of mineral absorption by allelochemicals are then discussed. 

Although several allelochemicals (primarily phenolic acids and flavonoids) have been shown to inhibit mineral absorption, only the phenolic acids have been studied at the physiological and biochemical levels to attempt to determine if mineral transport across cellular membranes can be affected directly rather than indirectly. Similar and even more definitive experiments need to be conducted with other allelochemicals that are suspected of inhibiting mineral absorption. Membrane vesicles isolated from plant cells are now being used to elucidate the mechanism of mineral transport across the plasma membrane and tonoplast (67, 68). Such vesicle systems actively transport mineral ions and thus can serve as simplified systems to directly test the ability of allelochemicals to inhibit mineral absorption by plant cells. 

To this outline must be added the need for information on the safe disposal of industrial wastes containing commercially insignificant, but perhaps physiologically important, residues of the compound. If such disposal involves production of new substances— for example, when wastes are burned—the hazard from these substances needs definition. 

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