Final answer:
The glomerulus is the structure in the kidney that filters the plasma and eliminates waste, forming part of the nephron, which is the kidney's functional unit.
Step-by-step explanation:
The structure in the kidney that filters a portion of the plasma and eliminates its wastes is the glomerulus. The glomerulus is part of the nephron, which is the functional unit of the kidney responsible for filtering the blood and forming urine. Blood enters the nephron through the glomerulus, a tuft of capillaries that effectively filters the blood based on particle size, allowing water and small molecules to pass into Bowman's capsule while larger components like blood cells and proteins are retained in the blood.
Following filtration at the glomerulus, the filtrate enters the proximal convoluted tubule where it undergoes further processing, including osmosis and active transport, to reclaim water and vital compounds back into the blood. This part of the nephron and its associated capillary network work hand in hand to ensure efficient filtration and reabsorption. Eventually, the modified filtrate is collected as urine and flows down towards the renal papilla, leading to the ureter for excretion from the body.