Caption

Glomerulus. Coloured Scanning Electron Micrograph (SEM) of a glomerulus - a tight knot of blood capillaries (yellow) inside one of the kidney's microscopic blood-filtering units. The glomerulus is where blood passing through the kidneys is filtered. Fluid passes out of the capillaries into the cavity of the surrounding Bowman's capsule (pink) and drains into a long tube, from which essential substances and some water are reabsorbed. The remaining unwanted fluid drains to the bladder as urine. Magnification; x555 at 6x7cm size.