What is the Structure of Human Kidney? Labeled Diagram and Functions Explained for NEET

Kidney Diagram Labeled with Functions – Structure & NEET Notes

The kidney is a vital excretory organ in humans. Understanding its labeled structure and functions is extremely important for Class 10, Class 11, and NEET Biology.

Structure of Human Kidney

Each human kidney is bean-shaped and located in the abdominal cavity. Internally, it is divided into two main regions:

• Cortex – Outer dark region
• Medulla – Inner light region with renal pyramids

Labeled Parts of Kidney & Their Functions

Part	Function
Renal Capsule	Protective outer covering
Cortex	Contains nephrons (filtration)
Medulla	Contains loops of Henle and collecting ducts
Renal Pyramid	Transports urine to renal pelvis
Renal Pelvis	Collects urine and passes it to ureter
Ureter	Carries urine to urinary bladder
Hilum	Entry/exit point for blood vessels and ureter

Structure of Nephron (Functional Unit)

• Glomerulus – Filters blood
• Bowman’s Capsule – Collects filtrate
• Proximal Convoluted Tubule (PCT) – Reabsorbs useful substances
• Loop of Henle – Concentrates urine
• Distal Convoluted Tubule (DCT) – Fine-tunes salt and water balance
• Collecting Duct – Final urine concentration

Main Functions of Kidney

• Excretion of nitrogenous wastes (urea, uric acid, creatinine)
• Regulation of water and salt balance
• Maintenance of blood pressure (via renin)
• Regulation of pH (acid-base balance)
• Production of erythropoietin (stimulates RBC formation)

NEET Important Points

• Each kidney contains about 1 million nephrons.
• Ultrafiltration occurs in the glomerulus.
• ADH and Aldosterone regulate urine concentration.
• Juxtaglomerular apparatus (JGA) regulates blood pressure.

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