Functional and structural unit of kidney are nephrons. Each nephron consists of malpighian body and tubule. Tubule of nephron consists of proximal convoluted tubule, descending limb, ascending limb and distal convoluted tubule. Loop of Henie has descending and ascending limb. Which involve in selective reabsorption of many substances like water (95% is absorbed); glucose, amino acid. So it takes part in conservation of water.