The rift valley contains the Jordan River and the Dead Sea, which separates Jordan from Israel and the Palestinian Territories. Jordan has a 26 kilometres (16 mi) shoreline on the Gulf of Aqaba in the Red Sea, but is otherwise landlocked.
Antidiuretic hormone binds to receptors on cells in the collecting ducts of the kidney and promotes reabsorption of water back into the circulation. In the absense of antidiuretic hormone, the collecting ducts are virtually impermiable to water, and it flows out as urine.
1 The proximal convoluted tubule and the ascending loop of Henle reabsorb most of the calcium in tubular filtrate into the blood. 2  Parathyroid hormone increases the reabsorption of calcium in the kidneys when blood calcium levels become too low.