nefronului

The nephron is the functional unit of the kidney. Each kidney contains approximately one million nephrons, which are microscopic structures responsible for filtering blood and producing urine. A nephron consists of two main parts: the renal corpuscle and the renal tubule. The renal corpuscle, also known as the Malpighian body, is where filtration occurs. It is composed of the glomerulus, a network of capillaries, and Bowman's capsule, a cup-shaped structure that surrounds the glomerulus. Blood enters the glomerulus through the afferent arteriole and leaves through the efferent arteriole. Under pressure, water and small solutes from the blood are filtered into Bowman's capsule, forming the glomerular filtrate.

The renal tubule extends from Bowman's capsule and is further divided into three sections: the proximal convoluted tubule, the loop of Henle, and the distal convoluted tubule. As the filtrate travels through these tubules, essential substances like glucose, amino acids, and most of the water are reabsorbed back into the bloodstream. Simultaneously, waste products and excess ions are secreted from the blood into the tubule. This selective reabsorption and secretion process modifies the filtrate, concentrating waste and forming urine. The distal convoluted tubules then empty into collecting ducts, which merge to form larger ducts that carry urine to the renal pelvis for excretion. The nephron's intricate structure and function are vital for maintaining the body's fluid balance, electrolyte levels, and eliminating metabolic waste.