Nephron: Function and Structure
The nephron is the functional unit of the kidney responsible for filtering blood and producing urine. It consists of a complex structure with specific regions that play distinct roles in the process of urine formation.

Structure of Nephron
- Renal Corpuscle: The initial part of the nephron where blood is filtered. It consists of the glomerulus, a network of capillaries, and Bowman's capsule, a cup-shaped structure that surrounds the glomerulus.
- Proximal Convoluted Tubule (PCT): Located after the renal corpuscle, the PCT reabsorbs essential substances like glucose, ions, and water back into the blood.
- Loop of Henle: This U-shaped structure is responsible for creating a concentration gradient in the kidney, allowing for water reabsorption in the collecting duct.
- Distal Convoluted Tubule (DCT): After the loop of Henle, the DCT further regulates the reabsorption of ions and water based on the body's needs.
- Collecting Duct: The final part of the nephron where urine is collected and transported to the renal pelvis for excretion.

Function of Nephron
- Filtration: Blood enters the nephron through the glomerulus, where small molecules like water, ions, and waste products are filtered into Bowman's capsule.
- Reabsorption: Essential substances are reabsorbed in the PCT, loop of Henle, and DCT to maintain the body's balance of water and ions.
- Secretion: Additional waste products and substances are actively transported into the nephron for excretion in the urine.
- Concentration: The loop of Henle establishes a concentration gradient that allows for water reabsorption in the collecting duct, leading to the production of concentrated urine.