What are glomeruli?

Glomeruli are indeed clusters of capillaries where blood is filtered. They play a crucial role in the kidneys, specifically in the nephron, which is the functional unit responsible for processing blood and forming urine. The glomerulus filters blood by allowing water and small solutes to pass through while retaining larger molecules like proteins and blood cells. This filtering process is the initial step in the formation of urine and is essential for removing waste products and regulating fluid balance in the body.

The structure of the glomeruli contributes to their function; they have a high surface area due to their capillary networks, which enhances their ability to filter blood efficiently. Understanding the role of glomeruli is fundamental when studying kidney function and disorders related to filtration, such as glomerulonephritis, which can affect the kidneys' ability to filter blood properly.