Final answer:
The bicarbonate/carbonic acid buffering system maintains blood pH within a narrow range by absorbing excess H+ or OH-, necessary for survival and normal bodily function. It also enables adaptation to varying altitudes, where it regulates CO2 and pH balance, in collaboration with the respiratory and renal systems.
Step-by-step explanation:
The bicarbonate/carbonic acid buffering system is an important physiological buffer in the human body because it effectively maintains blood pH within a narrow and vital range. This system can absorb excess hydrogen ions (H+) or hydroxide ions (OH-), which keeps the pH of the blood and extracellular fluid stable. Bicarbonate (HCO3-) reacts with excess H+ to form carbonic acid (H2CO3), which is then released as carbon dioxide (CO2) and exhaled. This mechanism ensures that the ingestion or inhalation of acidic or basic substances does not cause harmful fluctuations in the body's pH.
The buffer's ability to moderate pH changes is crucial for normal bodily function and survival, particularly under conditions such as living at high altitudes where the partial pressures of oxygen and CO2 differ from sea level.
Together with the respiratory system and the kidneys, the buffering system regulates acid-base balance through processes that affect carbonic acid levels and bicarbonate concentration, respectively. Without such a robust buffer system, the body's pH would vary significantly, potentially resulting in severe injury or death due to metabolic disturbances.