What is the normal pH range of blood?

What is the normal pH range of blood?

• A. 7.0 to 7.2
• B. 7.35 to 7.45
• C. 7.5 to 7.6
• D. 7.25 to 7.35

Answer: (B)

Blood pH is tightly regulated and stays within a narrow range around 7.35 to 7.45. This window keeps enzymes functioning properly and supports stable metabolic and physiological processes, including oxygen delivery and CO2 transport. Because the pH scale is logarithmic, even small shifts in hydrogen ion concentration represent meaningful changes in acidity or basicity, so the body uses buffering systems, plus respiratory and renal adjustments, to stay in this zone. If pH falls below 7.35, the blood becomes acidemic (acidosis); if it rises above 7.45, it becomes alkalemic (alkalosis). The bicarbonate buffering system, along with adjustments in breathing to control CO2 and kidney handling of H+ and bicarbonate, maintains this balance. Values outside this range indicate an abnormal state and can disrupt cellular functions, while the 7.35–7.45 range reflects the normal arterial blood pH. The other ranges are too acidic or too alkaline to be considered normal.

Blood pH is tightly regulated and stays within a narrow range around 7.35 to 7.45. This window keeps enzymes functioning properly and supports stable metabolic and physiological processes, including oxygen delivery and CO2 transport. Because the pH scale is logarithmic, even small shifts in hydrogen ion concentration represent meaningful changes in acidity or basicity, so the body uses buffering systems, plus respiratory and renal adjustments, to stay in this zone. If pH falls below 7.35, the blood becomes acidemic (acidosis); if it rises above 7.45, it becomes alkalemic (alkalosis). The bicarbonate buffering system, along with adjustments in breathing to control CO2 and kidney handling of H+ and bicarbonate, maintains this balance. Values outside this range indicate an abnormal state and can disrupt cellular functions, while the 7.35–7.45 range reflects the normal arterial blood pH. The other ranges are too acidic or too alkaline to be considered normal.