What organ is responsible for filtering blood in the human body?

The kidneys are the primary organs responsible for filtering blood in the human body. They play a crucial role in maintaining the body’s overall homeostasis by filtering out waste products, excess substances, and toxins from the blood, which are then excreted as urine. Each kidney contains approximately one million functional units called nephrons, which are responsible for the filtration process.

As blood passes through the kidneys, it undergoes a series of filtration steps that separate beneficial molecules, water, and electrolytes from waste materials. This filtration not only helps in the removal of toxins but also supports the regulation of blood pressure, electrolyte balance, and overall fluid balance in the body.

The liver also plays an important role in detoxifying harmful substances but is primarily responsible for metabolizing nutrients and producing bile. The heart is responsible for pumping blood throughout the body, while the lungs facilitate the exchange of gases (oxygen and carbon dioxide) rather than filtering blood. This understanding emphasizes the kidneys' unique and vital function in the body's system for maintaining internal equilibrium.