What is the normal arterial blood pH range?

What is the normal arterial blood pH range?

• A. 7.25-7.35
• B. 7.35-7.45
• C. 7.50-7.60
• D. 7.28-7.38

Answer: (B)

Arterial pH is tightly regulated because enzymes, ion balance, and overall cellular function depend on staying within a very narrow window. The normal arterial pH range is about 7.35 to 7.45. Within this range, the body’s buffering systems and regulatory controls—breathing to adjust CO2 and the kidneys to manage bicarbonate and hydrogen ion excretion—work together to keep pH stable. If the pH falls below 7.35, the blood becomes acidemic, which can disrupt enzyme activity and muscle function. If the pH rises above 7.45, the blood becomes alkalemic, increasing neuromuscular excitability and causing other problems. The other ranges listed fall outside the normal interval: they indicate acidemia or alkalemia rather than a normal arterial pH.

Arterial pH is tightly regulated because enzymes, ion balance, and overall cellular function depend on staying within a very narrow window. The normal arterial pH range is about 7.35 to 7.45. Within this range, the body’s buffering systems and regulatory controls—breathing to adjust CO2 and the kidneys to manage bicarbonate and hydrogen ion excretion—work together to keep pH stable.

If the pH falls below 7.35, the blood becomes acidemic, which can disrupt enzyme activity and muscle function. If the pH rises above 7.45, the blood becomes alkalemic, increasing neuromuscular excitability and causing other problems. The other ranges listed fall outside the normal interval: they indicate acidemia or alkalemia rather than a normal arterial pH.