Take a pill or certain fruits have a good amount
The glial cells forming myelin sheaths are called oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system. The gaps (approximately 1 micrometer wide) formed between myelin sheath cells long the axons are called Nodes of Ranvier.
hope this helps :p
If you mean the circulatory system then another name for it is cardiovascular system