Kidney Development (VIDEO) University of Southern California This video is under embargo. Please login to access this video. Caption Kidney development begins with a population of 'progenitor cells' (green), which are similar to stem cells. Some progenitor cells (red) stream out and aggregate into a ball, the renal vesicle (gold). As each renal vesicle grows, it radically morphs into a series of shapes -- can you spot the two S-shaped bodies (green-orange-pink structures) -- and finally forms a nephron. Each human kidney contains one million mature nephrons, which form an expansive tubular network (white) that filters the blood, ensuring a constant environment for all of our body's functions. Credit Video courtesy of Nils Lindstorm, Andy McMahon, Seth Ruffins and the Microscopy Core Facility at the Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at the Keck School of Medicine of USC Usage Restrictions Please use credit as is. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.