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.
The critical regulation of the body's salt, potassium and acid content is performed by the kidneys. The kidneys also produce hormones that affect the function of other organs. For example, a hormone produced by the kidneys stimulates red blood cell production. Other hormones produced by the kidneys help regulate blood pressure and control calcium metabolism.