Kidney glomeruli. Light microscope of a section through the cortex of a healthy kidney showing glomeruli. The core of a glomerulus is formed of a tightly coiled capillary (purple). The function of the glomeruli is to filter waste products from the blood. After the reabsorption of certain substances elsewhere in the kidney, the liquid is transported to the bladder as urine. Magnification: x500 when printed 10cm wide.