Homeostasis Homeostasis is responding to changes in the conditions of the external environment and the internal environment. Homeostasis works to maintain the organism's internal environment within tolerance limits; the range of conditions where the body's processes are able to function at a level that would allow life to continue in that organism. The respiratory, cardiovascular, and muscular systems are all controlled by homeostasis. Changes in the activities of the cardiovascular system are often a result …showed first 75 words of 436 total…

…showed last 75 words of 436 total…to maintain a constant level of physical output to achieve homeostasis. However, it can only work within tolerable limits, where extreme conditions can disable the negative feedback mechanism. In complex organisms, such as humans, it involves constant monitoring and regulating of numerous factors, including the gases oxygen and carbon dioxide, nutrients, hormones, and organic and inorganic substances. The concentrations of these substances in body fluid remain unchanged, within limits, despite changes in the external environment.