What is the normal pH range of human blood?

The normal pH range of human blood is vital for maintaining various physiological processes and ensuring proper function of enzymes and metabolic pathways. A pH of 7.35 to 7.45 indicates a slightly alkaline environment, which is essential for bodily functions, particularly in maintaining acid-base balance. This range is tightly regulated by several mechanisms, including respiration and renal function, because deviations outside of this range can lead to acidosis (if pH drops below 7.35) or alkalosis (if pH rises above 7.45), both of which can have serious health consequences.

The other ranges provided do not accurately reflect the normal pH of human blood. For example, a range of 6.5 to 7.0 and 7.0 to 7.25 would indicate a much more acidic state, while a range of 7.5 to 8.0 signifies a level of alkalinity that is not sustainable for human life. Thus, the range of 7.35 to 7.45 is the correct and physiologically relevant standard for blood pH.