pH of blood is in the range of?

Appeared in: BSF Staff Nurse - 2015

Explanation

The normal pH of arterial blood is tightly regulated between 7.35 and 7.45.
This slightly alkaline environment is essential for the proper functioning of enzymes, cellular metabolism, and oxygen delivery to tissues.
The body's buffer systems, along with the lungs (respiratory system) and kidneys (renal system), work together to maintain this delicate balance.
Values outside this range indicate an acid-base imbalance that requires clinical attention.

Option A: A pH range of 7.0 to 7.1 is neutral to slightly acidic. This represents severe, life-threatening acidosis and is far below the normal physiological range for blood.
Option B: A pH range of 7.25 to 7.35 is entirely within the acidotic range. Any value below 7.35 indicates acidosis, an excess of acid in the blood.
Option D: A pH range of 7.50 to 7.60 is entirely within the alkalotic range. Any value above 7.45 indicates alkalosis, an excess of base in the blood.

Clinical Relevance

Nursing practice connection: Knowing Normal blood pH range and principles of acid-base balance helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Nurses frequently monitor Arterial Blood Gas (ABG) results to assess a patient's acid-base status, especially in critical care, post-operative, or respiratory distress situations.
Deviations from the normal pH range can be the first sign of serious underlying conditions like diabetic ketoacidosis, kidney failure, or severe lung disease.
What if? If a patient with an anxiety attack is hyperventilating and has a pH of 7.52, the nurse would recognize this as respiratory alkalosis. The priority intervention would be to help the patient slow their breathing (e.g., using a paper bag or coaching) to retain CO₂ and normalize the pH.

How to Approach the Question

This is a factual recall question testing your knowledge of a fundamental physiological value.
First, identify the core concept being asked: the normal pH of blood.
Recall from your studies that blood is slightly alkaline (basic). This means its pH must be slightly above the neutral value of 7.0.
Evaluate the options based on this knowledge. Options A (7.0-7.1) and B (7.25-7.35) are either neutral or trending towards acidic.
Remember the specific, narrow range for normal arterial blood pH.
Select the option that precisely matches the established physiological range of 7.35 to 7.45.

Concept Tested & Keywords

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E6 Nursing Fundamentals Potter Perry 12e Part 5 p. 54-56

E6 Physiology Guyton 4SAE Part 2B p. 66-68

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