Which of the following organ is one of the primary regulator of body fluid and electrolyte balance?

AIIMS Patna NO - 2020

Applied Physiology

Easy

Appeared in: AIIMS Patna NO - 2020

Explanation

The kidneys are the principal organs for regulating fluid volume, osmolality, and electrolyte balance.
They achieve this by filtering approximately 180 liters of plasma daily, selectively reabsorbing what the body needs, and excreting the rest as urine.
Key functions include regulating Extracellular Fluid (ECF) volume, electrolyte levels (like sodium, potassium), and the pH of the ECF.
This regulatory function is essential for maintaining homeostasis, the stable internal environment necessary for cells to function correctly.

Option A: The intestine is primarily involved in the absorption of water and nutrients from food and drink, not the active regulation of the body's overall balance. While it plays a role in intake, it does not fine-tune excretion based on the body's needs.
Option C: The stomach's main role is to begin the process of digestion by secreting acid and enzymes. It has a negligible role in the overall regulation of the body's fluid and electrolyte balance.
Option D: The lungs are crucial for regulating acid-base balance by controlling the exhalation of carbon dioxide. They also contribute to 'insensible water loss' through breathing, but they do not regulate fluid and electrolyte levels in the same way the kidneys do.

Clinical Relevance

Nursing practice connection: Knowing Primary organ for fluid and electrolyte regulation helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Nurses constantly monitor a patient's fluid and electrolyte status by tracking intake and output, daily weights, and assessing for signs of imbalance like edema (fluid excess) or poor skin turgor (dehydration).
Understanding the kidney's role is critical for interpreting lab results, such as serum creatinine, Blood Urea Nitrogen (BUN), and electrolyte levels (Na+, K+), which directly reflect renal function.
What if a patient is in renal failure? The nurse must anticipate severe disruptions in fluid and electrolyte balance. This includes monitoring for hyperkalemia (high potassium), which can cause fatal cardiac arrhythmias, and fluid overload, leading to hypertension and pulmonary edema. Interventions like dialysis become necessary to perform the regulatory functions the kidneys no longer can.

How to Approach the Question

First, identify the key concepts in the question: 'primary regulator' and 'fluid and electrolyte balance'.
Consider the main function of each organ listed in the options.
The intestine absorbs, the stomach digests, and the lungs handle gas exchange. While these processes can affect fluid levels, they are not the primary regulatory mechanisms.
Recall that the kidneys' function is to filter blood and produce urine. This process is specifically designed to adjust the volume and composition of body fluids.
Conclude that the kidney is the only organ whose principal role is the active and precise regulation of body fluid and electrolytes.

Concept Tested & Keywords

Q0WgbpNtWmzlJofzsyCM1G

E6 Nursing Fundamentals Taylor p. 774-776

E6 Physiology Guyton 4SAE Part 2B p. 10-11

E6 Nursing Brunner Adult Health 3SA Vol 1 Part 1 p. 137-139