What part of the kidney filters blood to remove waste and regulate water and electrolyte concentrations?

The nephron is the fundamental functional unit of the kidney responsible for filtering blood, removing waste, and regulating water and electrolyte concentrations. Each nephron consists of several components, including the glomerulus and the tubules, that work together to accomplish these essential tasks.

The glomerulus plays a crucial role as the initial filtering unit within the nephron, where blood is filtered through a network of capillaries. However, the entire nephron unit – including the glomerulus, proximal tubule, loop of Henle, distal tubule, and collecting duct – is responsible for the comprehensive functions of filtration, reabsorption, and secretion. The distal parts of the nephron help fine-tune the reabsorption of water and various electrolytes based on the body's needs.

Other parts mentioned, such as the renal pelvis, are involved in collecting urine before it is sent to the bladder but do not perform filtration themselves. Each component of the nephron works in concert to maintain homeostasis within the body, ultimately impacting blood composition and volume.