(June 2011). The nephron (from Greek νεφρός - nephros, meaning kidney) is the basic structural and functional unit of the kidney. Its chief function is to regulate the concentration of water and soluble substances like sodium salts by filtering the blood, reabsorbing what is needed and excreting the rest as urine.omposed of a glomerulus and the Bowman's capsule, the renal corpuscle (or Malpighian corpuscle) is the beginning of the nephron. It is the nephron's initial filtering component. The glomerulus is a capillary tuft that receives its blood supply from an afferent arteriole of the renal circulation.