is dependent on which causes interstitial fluid to be hypertonic to the filtrate. is a process in which useful, dissolved substances are moved from the filtrate into peritubular capillaries. takes place along all renal tubule locations, but most takes place in the proximal convoluted tubules. adds additional nitrogen-containing waste solutes, such as urea, into the filtrate. depends on the secretion of antidiuretic hormone (ADH). takes place across the walls of the glomeruli. may be controlled, in part, by the finger-like extensions of podocytes. is a process in which blood pressure forces water and some dissolved substances out of the blood into the glomerular capsule.