Glomerulus Coloured Scanning Electron Micrograph SEM of a glomerulus a tight knot of blood capillaries yellow inside one of the kidneys microscopic bloodfiltering units The glomerulus is where blood passing through the kidneys is filtered Fluid passes out of the capillaries into the cavity of the surrounding Bowmans 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 x at xcm size