The urinary system, also known as the excretory system, is responsible for removing excess water, waste, and toxins from the blood, consisting of organs such as the kidneys, ureters, urinary bladder, and urethra. The kidneys filter blood, produce urine, and secrete important hormones like erythropoietin and renin to regulate blood pressure and red blood cell production. This system maintains fluid and electrolyte balance, and is essential for various metabolic processes alongside its excretory functions.