What is the process called that the kidneys use to filter waste from the blood?

The process utilized by the kidneys to filter waste from the blood is known as filtration. This primary function occurs in the glomeruli, which are tiny blood vessels located within the nephrons, the functional units of the kidneys. During filtration, blood pressure forces water, waste products, and small molecules through the walls of these capillaries and into the Bowman's capsule, where the filtrate begins its journey through the nephron.

This step is crucial for the subsequent processes of reabsorption and secretion, which refine the filtrate and help maintain the body's electrolyte balance and fluid levels. Without filtration, the kidneys would not be able to effectively remove toxic substances and excess materials from the bloodstream, leading to a build-up of wastes and an inability to maintain homeostasis. Therefore, understanding filtration is key to grasping how the kidneys function and their role in overall body health.