This is where buffers play a normal vital role by guarding against this shift toward acidosis and helping keep blood and body pH in the normal range regardless of its arterial or venous source. Recall that systemic venous blood is high in acidic carbon dioxide and should be low in pH. Similarly, systemic venous blood is low in carbon dioxide and should be alkaline. In fact, the two are strikingly similar in pH primarily due to buffers. Explain the physiological impact of chronic vomiting on body pH. Explain the physiological impact of chronic diarrhea on body pH. Compare the carbon dioxide content of systemic and pulmonic arterial and venous blood and explain why their pH s are similar. The two metabolic acids mentioned above, carbonic and lactic, are chemically different in an important way.
Carbonic acid is described as a volatile acid since it has a vapor phase.
Since carbon dioxide is a common waste product, this is a valuable process in both pH regulation and compensation. The kidneys participate in normal pH regulation by the secretion of hydrogen ions into the urine as blood is processed by nephrons. In contrast, lactic acid is nonvolatile and must be eliminated via the kidneys. Importantly, most of the carbon dioxide transported in circulating blood is carried as the bicarbonate ion as a result of the bicarbonate buffer system. This ion is in itself alkaline since it can accept a hydrogen ion to become carbonic acid and contributes to a normal base excess in the body.