Kidney glomeruli, coloured scanning electron micrograph (SEM). Glomeruli are made up of a tight knot of blood capillaries covered with podocyte cells (red and yellow), whose swollen nuclei and thin interweaving extensions (pedicles) are seen here. These tiny filtration units remove toxic waste products from the blood. Filtration occurs through slits between the interlocking pedicles. Filtered fluid then passes into the cavity of the surrounding Bowman's capsule, and drains to the bladder as urine. Magnification: x1750 when printed 10 centimetres wide.