what are the two primary functions of kidneys
While filtering, the kidneys produce urine to carry the toxins away. The urine is sent through two tubes called ureters down to the bladder, where the urine then leaves the body through the urethra. The kidneys also make hormones. These hormones help regulate blood pressure, make red blood cells and promote bone health.
In this way, your kidneys regulate the body's level of these substances. The right balance is necessary for life, but excess levels can be harmful. In the nephron (left), tiny blood vessels intertwine with urine-collecting tubes. Each kidney contains about 1 million nephrons. In addition to removing wastes, your kidneys release three important hormones: 1  Erythropoietin (eh-RITH-ro-POYeh-tin), or EPO, which stimulates the bones to make red blood cells. 2  Renin (REE-nin), which regulates blood pressure.