Which of the following represents a normal arterial pH range?

Which of the following represents a normal arterial pH range?

• A. 7.35-7.45
• B. 7.20-7.40
• C. 7.50-7.60
• D. 7.10-7.30

Answer: (A)

Arterial pH is tightly regulated within a narrow window because even small changes can disrupt enzyme function and how cells work. The normal arterial pH is about 7.35 to 7.45, a range that keeps proteins and metabolic processes operating correctly and supports stable cardiovascular and respiratory function. Values below 7.35 indicate acidosis, while values above 7.45 indicate alkalosis. Among the options, 7.35 to 7.45 is the only range that stays within this normal zone. The other ranges are outside: 7.20–7.40 sits too low on the scale, 7.50–7.60 is clearly alkaline, and 7.10–7.30 reflects significant acidosis.

Arterial pH is tightly regulated within a narrow window because even small changes can disrupt enzyme function and how cells work. The normal arterial pH is about 7.35 to 7.45, a range that keeps proteins and metabolic processes operating correctly and supports stable cardiovascular and respiratory function. Values below 7.35 indicate acidosis, while values above 7.45 indicate alkalosis. Among the options, 7.35 to 7.45 is the only range that stays within this normal zone. The other ranges are outside: 7.20–7.40 sits too low on the scale, 7.50–7.60 is clearly alkaline, and 7.10–7.30 reflects significant acidosis.