Functional unit of Kidney is?

Appeared in: NHM MP Staff Nurse - 2015

Explanation

The nephron is the microscopic structural and functional unit of the kidney, responsible for urine formation.
Each kidney contains approximately 1 to 1.5 million nephrons, which allows for adequate renal function even with some loss.
The primary role of the nephron is to regulate water and soluble substances by filtering blood, reabsorbing what is needed, and excreting the rest as urine.
A nephron consists of two main parts: a renal corpuscle (which includes the glomerulus) and a renal tubule (which includes the PCT, Loop of Henle, and DCT).

Option B: A neuron is the basic working unit of the nervous system, responsible for transmitting nerve impulses.
Option C: The Proximal Convoluted Tubule (PCT) is only the first segment of the renal tubule. It is a part of the nephron, not the entire functional unit.
Option D: The Distal Convoluted Tubule (DCT) is a later segment of the renal tubule. It is a part of the nephron, not the entire functional unit.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Anatomy and Physiology of the Renal System as background academic context rather than a clinical decision trigger.
Understanding nephron function is crucial for interpreting renal function tests like the Glomerular Filtration Rate (GFR). A normal GFR is approximately 125 mL/min, which reflects the combined filtration rate of all functioning nephrons.
Damage to nephrons from chronic conditions like diabetes or hypertension leads to Chronic Kidney Disease (CKD). Nurses play a key role in monitoring patients for signs of declining renal function, such as rising creatinine levels and decreasing GFR.
What if? If a patient's urine output drops below 0.5 mL/kg/hr (oliguria), it is a critical sign of acute kidney injury (AKI). The nurse's priority is to assess for causes (like dehydration or obstruction) and report this finding immediately, as it signals significant nephron dysfunction and risk of renal failure.

How to Approach the Question

First, identify the keywords in the question stem: 'Functional unit' and 'Kidney'.
This is a direct factual recall question based on fundamental anatomy and physiology.
Mentally review the basic structural units of major organ systems to find the match for the kidney.
Evaluate the given options: 'Neuron' is the unit of the nervous system. 'PCT' and 'DCT' are parts of the kidney's functional unit, but not the whole unit itself.
Based on this elimination process, conclude that 'Nephron' is the correct term for the entire functional unit of the kidney.

Concept Tested & Keywords

QVrPvkcdBN8DwhAtnm7fJJ

E6 Anatomy Applied Ashalatha 4e p. 361-363

E6 Nursing Brunner Adult Health 3SA Vol 2 Part 1 p. 122-124

Practise the full NHM MP Staff Nurse - 2015

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