2. Body Maintenance Of Normal pH
In order to maintain a proper pH in the bodily fluids, and so that acidosis or alkalosis will not manifest, three major physiological control systems exist within the body. The first mechanism involves a buffer system for the hydrogen ion fluctuations. All bodily fluids are supplied with acid-base buffers which combine with any acid or alkaline substance and prevent excessive change in the hydrogen ion concentration.
Another mechanism the body uses to maintain normal pH is within the respiratory system. When the hydrogen ion concentration (H + ) changes measurably, the respiratory system is immediately stimulated to alter the rate of pulminary ventilation. This brings about a change in the quantity of carbon dioxide (CO2) within the system. High levels of carbon dioxide in the system, as created when holding the breath or due to physiological impairments of respiration, increase the acidity of the bloodstream. Any disease that interferes with normal breathing, such as emphysema or asthma, will impede the release of CO2 from the lungs and, subsequently, this CO2 will combine with water to form carbonic acid. This increases the concentration of hydrogen ions, and thus the acidity of the blood is simultaneously increased.
The last of the three major physiological control systems of the body to maintain normal pH involves the kidneys. When the (H + ) (hydrogen concentration) deviates from a normal value, the kidneys excrete either an acid or alkaline urine. This serves to help readjust the (H + ) of the bodily fluids back toward the normal value.
The key point to keep in mind when you are trying to understand the terms acidosis and alkalosis is that, as was previously mentioned, when the hydrogen ion concentration (H + ) is above normal, there is a state of acidosis and when the (H + ) falls below normal, we have alkalosis. If either