Definition
The endoneurium is a layer of connective tissue that surrounds individual nerve fibers (axons) within a nerve. Think of it as the 'wrapping paper' around each nerve fiber. It provides support and insulation for each axon. It contains capillaries that supply blood to the nerve fibers. The endoneurium helps protect the delicate nerve fibers from damage. It creates a microenvironment that is optimal for nerve function. Without it, nerve signals could be disrupted.