There are two types of nephrons, the cortical nephrons, of which the loops of Henle reach only into the outer medulla, and the juxtamedullary nephrons, of which the loops of Henle reach into the inner medulla. RC, renal corpuscle; PCT, proximal convoluted tubules; PST, proximal straight tubules; DTL, thin descending limb (of the loop of Henle); ATL, thin ascending limb (of the loop of Henle); TAL, thick ascending limb (of the loop of Henle); DCT, distal convoluted tubule; CNT, connecting tubule; CD, collecting duct.