The normal pH value ranges from:

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2020

Explanation

The normal pH of human arterial blood is tightly regulated between 7.35 and 7.45.
This slightly alkaline range is essential for the optimal functioning of enzymes and various metabolic processes in the body.
A pH below 7.35 is defined as acidosis, while a pH above 7.45 is defined as alkalosis.
The body's buffer systems, along with the respiratory and renal systems, work together to maintain this narrow pH range.

Option A: This range (7.20 - 7.34) represents acidosis, a state where the blood is more acidic than normal.
Option C: This range (7.46 - 7.55) represents alkalosis, a state where the blood is more alkaline (basic) than normal.
Option D: This range (7.56 - 7.65) represents a more severe state of alkalosis and is significantly outside the normal physiological range.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Normal Blood pH and Acid-Base Balance as background academic context rather than a clinical decision trigger.
Nurses frequently use Arterial Blood Gas (ABG) analysis to assess a patient's acid-base status, which is critical in managing conditions like Diabetic Ketoacidosis (DKA), sepsis, and respiratory failure.
Monitoring pH is essential in critical care settings to guide treatments, such as mechanical ventilation settings or the administration of intravenous fluids and electrolytes.
What if? If a patient's ABG report shows a pH of 7.28, the nurse should immediately recognize this as acidosis, assess for respiratory or metabolic causes (by checking PaCO2 and HCO3−), and prepare for interventions like administering sodium bicarbonate or adjusting ventilator settings as per protocol.

How to Approach the Question

Identify the core of the question, which is asking for the 'normal pH value' range in the human body.
Recognize that this is a factual recall question based on a fundamental physiological parameter.
Recall the specific, narrow range for normal human blood pH that is essential for homeostasis.
Compare the recalled range (7.35-7.45) with the given options.
Eliminate the options that fall into the acidotic (less than 7.35) or alkalotic (greater than 7.45) ranges to select the correct answer.

Concept Tested & Keywords

QcSgbh0GKsi0C_ntG0j8FN

E6 Nursing Fundamentals Taylor p. 785-787

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

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 554-556

Practise the full RUHS, Jaipur, PB B.Sc Nursing Entrance-2020

Attempt every question from this paper in a timed mock, then review the full solution for each one.