Which organ is primarily responsible for filtering blood and producing urine?

The kidney is primarily responsible for filtering blood and producing urine. It plays a crucial role in regulating various body functions, including maintaining fluid and electrolyte balance, removing waste products from the bloodstream, and regulating blood pressure. The kidneys filter the blood to remove excess substances and toxins, which are then excreted as urine.

Other organs in the urinary system serve different functions; for example, the bladder's role is to store urine until it is excreted, while the ureter is responsible for transporting urine from the kidneys to the bladder. The liver, while vital for detoxification and metabolism, does not directly participate in urine production or blood filtration in the same way the kidneys do. Therefore, the kidney is uniquely suited to this essential function in the body.