glomerulu

A glomerulus (plural: glomeruli) is a specialized structure within the kidney involved in the process of blood filtration. It is a network of tiny blood vessels called capillaries, which are enclosed within a Bowman's capsule as part of the nephron, the functional unit of the kidney. The primary role of the glomerulus is to filter blood, allowing water, ions, nutrients, and waste products to pass into the nephron while retaining blood cells and large proteins.

The process begins when blood enters the afferent arteriole, which supplies the glomerulus. This causes blood to flow through the capillary network under pressure, facilitating the filtration of plasma into the surrounding Bowman's capsule. The filtered fluid, known as glomerular filtrate, then proceeds through the nephron for further processing, such as reabsorption and secretion, to produce urine.

The filtration barrier of the glomerulus is composed of three layers: the fenestrated endothelium of the capillaries, a basement membrane, and the podocytes—specialized cells with foot-like extensions that cover the capillaries and create filtration slits. This multilayered structure helps ensure selective filtration, preventing large molecules and cells from passing out of the bloodstream.

Disorders involving the glomerulus can lead to kidney diseases, including glomerulonephritis and diabetic nephropathy, which can impair kidney function and result in proteinuria, hematuria, or chronic kidney failure. The health of glomeruli is essential for maintaining the body's fluid and electrolyte balance and overall metabolic homeostasis.

Research into glomerular structure and function continues to provide insights into kidney physiology and potential treatments for glomerular diseases.