Acid – Base Balance

Acid – Base Balance

The H+ ion concentration has always to be kept with normal range, otherwise enzymatic activities might be affected as increasing or decreasing the level and this might either stimulate or depress the activity. In general the H+ concentration of extracellular fluid represented by blood is usually considered. However in the intracellular compartment and some other cells in the renal tubules might have higher concentration or lower pH.
The pH is usually considered of extracellular which is about 7.35-7.4, however, it might be as low as 6.8 and high as 7.8. these two limits are compatible with life.
Decreasing of pH below the normal range is known as acidosis and increase of pH above the normal range is known as alkalosis.
Normally the body has certain mechanisms in order to bring the pH value with normal limits, these are:
1. Buffer system.
2. Respiratory system.
3. Kidneys.
The most effective system present in the body is the buffer system, which act within 15 sec., however if buffer system is not enough to overcome the pH value, then the respiratory system starts to be involved in such a case, so either the respiratory rate increase or decrease. This is usually responding within 10 minutes and if these two mechanisms fail to adjust the pH of the body fluid, then the kidneys will be involved to excrete either an alkaline or an acidic urine.