<P> The nephron is the functional unit of the kidney . Each nephron is composed of a renal corpuscle, the initial filtering component; and a renal tubule that processes and carries away the filtered fluid . </P> <P> The renal corpuscle is the site of the filtration of blood plasma . The renal corpuscle consists of the glomerulus, and the glomerular capsule or Bowman's capsule . The renal corpuscle has two poles--a vascular pole and a urinary pole . </P> <P> The arterioles from the renal circulation enter and leave the glomerulus at the vascular pole . The glomerular filtrate leaves the Bowman's capsule at the renal tubule at the urinary pole . </P> <P> The glomerulus is the network known as a tuft, of filtering capillaries located at the vascular pole of the renal corpuscle in Bowman's capsule . Each glomerulus receives its blood supply from an afferent arteriole of the renal circulation . The glomerular blood pressure provides the driving force for water and solutes to be filtered out of the blood plasma, and into the space in Bowman's capsule called Bowman's space . </P>

Where does exchange of ions occur in the nephrone