I believe its large blue vessel also known as vena cava
It is transplanted routinely to treat a variety of blood and bone marrow diseases, blood cancers, and immune disorders. More recently, stem cells from the blood stream (called peripheral blood stem cells) and umbilical cord stem cells have been used to treat some of the same blood-based diseases
The carbon cycle describes the way the element carbon moves between the Earth's biosphere, hydrosphere, atmosphere, and geosphere. It is important for a few reasons: Carbon is an essential element for all life, so understanding how it moves helps us to understand biological processes and factors that influence them.
Source: Google
Hope this helps you :)
They will be clean from all salt because the new water contains no salt