Which organ is primarily responsible for filtering blood in humans?

The kidneys are primarily responsible for filtering blood in humans. They play a crucial role in maintaining the body's internal balance by removing waste products, excess substances, and toxins from the bloodstream. This filtering process occurs in tiny functional units within the kidneys called nephrons, where blood is processed to form urine.

In addition to waste filtration, the kidneys help regulate blood pressure, electrolyte balance, and red blood cell production through the secretion of various hormones. Their role in filtering blood is essential for maintaining overall health and ensuring that harmful substances do not accumulate in the body.