Which organ is responsible for filtering blood in the body?

The kidneys are the organs responsible for filtering blood in the body. They play a crucial role in maintaining the body's homeostasis by removing waste products and excess substances from the bloodstream. Each kidney contains approximately one million filtering units called nephrons, which work to filter out waste, excess salts, and fluids, ultimately forming urine to be excreted from the body.

Additionally, the kidneys help regulate electrolyte balance, blood pressure, and the body's overall fluid balance. Through this intricate filtering process, they are essential for purifying the blood and maintaining a healthy, functioning system. The liver detoxifies chemicals and produces important proteins, while the lungs are primarily involved in gas exchange, and the heart circulates blood throughout the body. Thus, the roles of the kidneys in blood filtration distinguish them as the primary organ for this function.