Final answer:
When the concentration of HCO3 falls below 22, it indicates metabolic acidosis. The body compensates for this by decreasing pCO2 levels to establish the proper ratio of bicarbonate and carbonic acid in the blood.
Step-by-step explanation:
When the concentration of HCO3 falls below 22, it indicates a condition called metabolic acidosis. Metabolic acidosis occurs when there are lower-than-normal levels of bicarbonate in the blood. In this condition, the pH of the blood decreases, leading to various symptoms such as headache, confusion, and fatigue. However, the body has mechanisms to compensate for this imbalance by decreasing the levels of pCO2. This helps to reestablish the proper ratio of bicarbonate and carbonic acid in the blood.