Which of the following is not correct in regard to potassium?

Appeared in: NVS- 2025

Explanation

This statement is factually incorrect, making it the right answer for a 'not correct' question.
An average adult human body contains approximately 250 grams of potassium, not 25 grams.
The value given in the option is off by a factor of ten, representing a significant factual error.

Option A: This is a correct statement. A diet rich in potassium protects against the adverse effects of high sodium, helping to reduce blood pressure.
Option C: This is a correct statement. Potassium is a known vasoactive ion that influences vascular tone, typically promoting vasodilation.
Option D: This is a correct statement. Endothelial cells release potassium, which acts as an endothelium-derived hyperpolarizing factor (EDHF) to induce smooth muscle relaxation.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Physiological properties and roles of potassium as background academic context rather than a clinical decision trigger.
Nurses must monitor serum potassium levels closely, as both hypokalemia (low potassium) and hyperkalemia (high potassium) can cause life-threatening cardiac arrhythmias.
Patient education on dietary sources of potassium (e.g., bananas, oranges, spinach, potatoes) is a key nursing intervention, especially for patients on diuretics or those with hypertension.
What if? If a patient is on a potassium-sparing diuretic like Spironolactone, the nurse's primary concern shifts from preventing hypokalemia to monitoring for hyperkalemia, and the patient should be advised to avoid high-potassium foods and salt substitutes containing potassium chloride.

How to Approach the Question

First, identify that the question uses a negative lead-in ('not correct'). This means you are looking for the false statement among the options.
Evaluate each option independently for its factual accuracy regarding the physiological role of potassium.
Recall or look up key facts: potassium's effect on blood pressure, its role as a vasoactive substance, its cellular location and total body amount.
Option A: Potassium's role in lowering blood pressure is a well-known dietary recommendation. This is likely true.
Option C & D: Potassium's vasoactive properties and release from endothelial cells are key physiological mechanisms. These are likely true.
Option B: Check the numerical value. A value of 25g seems low for a major electrolyte. The actual value is 250g. This statement is false.

Concept Tested & Keywords

Q4ODeLlaItViFGNcElK9DE

E6 Parks TextBook of Preventive & Social Medicine part 2 — Subpart A (pp 1-232 of 464) p. 157-159

E6 Physiology Guyton 4SAE Part 2B p. 61-63

Practise the full NVS- 2025

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