This is partially true. There are many contributing reasons but this is one.
Phlebitis Definition. Phlebitis (fle-BYE-tis) is a condition in which a vein becomes inflamed (phleb=vein + it is=inflammation). The inflammation may cause pain and swelling. When the inflammation is caused by a blood clot or thrombus, it is called thrombophlebitis.
92 of the elements are found naturally.
Explanation:
The cardiovascular system pumps blood throughout the body. As the blood is circulating out of the heart it is filled with oxygen and nutrients. These nutrients get divided to the rest of the cells in the body. As the blood is coming back into the heart the urinary system takes the waste out of it.
So basically, it basically acts as a delivery system delivering O2 and nutrients and takes waste out of the cell.