what are kidneys made of
Confidence votes 2.2K. The kidney is made of a majority of cells called nephrons. These are the basic cellular unit of the kindey. Nephrons filter out the toxins from the blood stream and produce urine. There are various chemicals that control the actions of the kidney.Some of these cause more of less water to be retained by the kidneys.idneys are internal organs whose function is to filter waste (primarily uric acid) out of the blood. The kidneys are bean-shaped organs, each about the size of a fist. They â¦ are located near the middle of the back, just below the rib cage, one on each side of the spine.