Nerves are composed of multiple fibers which in turn are composed of many, many axons. Each successive grouping of fibers is surrounded by connective tissue.
Axons are the long branches of nerves cells which transmit electrochemical impulses from one nerve to another or to and from target organs.
The axons are surrounded by myelin, a kind of insulating material formed by oligodendrocytes. In diseases in which myelin is destroyed, electrochemical conduction is impossible, and even if the nerve fibers do not die, they are ineffective.
Blood vessels travel through the mesoneurium and then divide into capillaries within the nerve to deliver oxygen and nutrients.
Nerves are vulnerable to trauma, reduced oxygen levels, and diabetes.