Which is not found in urine of healthy adult?

RRB Staff Nurse Delhi-2015

Applied Physiology

Medium

Appeared in: RRB Staff Nurse Delhi-2015

Explanation

In a healthy adult, the kidneys effectively filter waste while retaining essential substances and large molecules.
Glucose, although filtered by the glomerulus, is completely reabsorbed back into the bloodstream by the renal tubules.
Proteins and Red Blood Cells (RBCs) are too large to pass through the healthy glomerular filtration barrier.
Therefore, the absence of all three—glucose, protein, and RBCs—is expected in a healthy individual's urine, making 'all of the above' the correct and most comprehensive answer.

Option A: This option is incomplete. While it is true that glucose is not found in healthy urine, protein and red blood cells are also absent.
Option B: This option is incomplete. While it is true that protein is not found in healthy urine, glucose and red blood cells are also absent.
Option C: This option is incomplete. While it is true that red blood cells are not found in healthy urine, glucose and protein are also absent.

Visual 1: Diagram: A detailed illustration of a nephron, highlighting the glomerulus (filtration site) and the proximal convoluted tubule (reabsorption site for glucose).
Visual 2: Infographic: A comparative chart showing a normal urinalysis report versus abnormal reports for diabetes (glycosuria), kidney disease (proteinuria), and UTI/trauma (hematuria).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Normal and abnormal constituents of urine as background academic context rather than a clinical decision trigger.
Urinalysis is a fundamental, non-invasive diagnostic tool that provides crucial insights into metabolic and kidney-related disorders.
Nurses are responsible for correct urine sample collection (e.g., midstream clean-catch), performing dipstick tests, and promptly reporting abnormal findings to the healthcare provider for further investigation.
What if? If a patient's dipstick shows trace protein, the nurse should consider transient causes like recent strenuous exercise, fever, or dehydration. However, persistent proteinuria requires follow-up as it can be an early sign of chronic kidney disease.

How to Approach the Question

First, identify the core of the question: what substances are normally absent in the urine of a healthy person.
Analyze the keyword 'not', which frames the question negatively. You are looking for things that shouldn't be there.
Evaluate each option based on your knowledge of renal physiology. Recall that glucose is reabsorbed, and proteins/cells are too large to be filtered.
Recognize that 'Only glucose', 'Only Protein', and 'Only Red blood cells' are all individually correct statements but are incomplete.
When multiple individual options are correct and an 'all of the above' option is available, it is often the most accurate and complete answer.

Concept Tested & Keywords

Concept Tested: Normal and abnormal constituents of urine
Stem keywords: urine, healthy adult, not found
Lead-in keywords: Which is not
Negative lead-in flag: The question uses the negative keyword 'not', requiring identification of substances that are absent from normal urine.

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