The detailed events associated with the differentiation of the nephrogenic mesenchyme are somewhat complex. It has been suggested that each terminal branch of the ureteric bud stimulates the associated cap mesenchyme tissue to form a renal vesicle (the most primitive stage of nephron development: a stage I nephron). This then elongates, becomes a comma-shaped and then an S-shaped body (stage II nephron), and makes contact with and fuses with the distal component of the ureteric bud. The latter then forms the collecting duct. One fold of the S-shaped body gives rise to Bowman's capsule (also termed the glomerular capsule). Soon afterwards, endothelial cells invade to make a capillary knot-like outgrowth, the glomerular tuft, which goes on to form the glomerulus. The inner epithelial layer of the Bowman's capsule (also called the visceral epithelium, or podocyte layer because it consists of podocytes) is closely apposed to the endothelial glomerulus. Together, the Bowman's capsule and the glomerulus comprise the definitive renal corpuscle. The rest of the nephron elongates to form components of the proximal tubule, the loop of Henle and the distal tubule. The distal pole of the developing nephron connects to the ureteric bud that induced it at an early stage of nephron/ collecting duct development, before differentiation of the proximal tubule, the loop of Henle and the distal tubule are complete. This connection allows the excretory products produced by the kidney to be removed and subsequently transferred, via the ureter, into the bladder where they are stored until it is appropriate to empty the bladder. [http://www.gudmap.org/About/Tutorial/DevMUS.html#DMK_Nephron]