The bowman's capsule, proximal convoluted tubule, and loop of henle are all parts of a:

These are all parts of the kidneys. The loop of henle is a U-shaped the part of the tubule that is believed to recover salt and water from the urine. The bowman's capsule is a double-walled filter that opens into the proximal convoluted tubule, the job of which is to aid re-absorption into the peritubular capillaries.