Microscopic filtering units in the kidney are called . The artery carries blood to the kidney and branches of this artery carry this blood to the first part of the nephron, ___, ___, ___, and other substances ___, which passes the substances into the ___. As these materials pass through various sections of the tubule, substances needed by the body are and returned to blood . Excess products such as ___ and ___, some , and ___ remain in the tubule and become known as the concentrated waste liquid called ___.