Kidney filtration network. False-colour scanning electron micrograph of podocytes, the filtration units of the glomerulus in the renal corpuscle. Podocytes have large smooth nuclei from which depart long and narrow branches known as primary processes. These in turn give rise to short secondary foot processes (pedicels) which closely interdigitate with those of other primary processes. Podocytes completely surround the capillary system of the renal corpuscle and it is through the gaps between the pedicels that about 100 litres of blood are filtered every hour. Magnification: x2230 at 6x7cm size.