My Dictionary

Nervous tissue is definitely one intriguing subject as it is controls functions that begin with the external environment and get interpreted by the brain. Although, it is an interesting subject, there are some terms that get a little confusing as they are similar but location can differentiate them. For example:

Oligodendrocytes are cells of the central nervous system that work to support axons and create a myelin sheath to insulate the axon. The myelin sheath wraps around multiple axons and insulates them to guarantee the quick conduction of nerve impulses.
Schwann Cells have the same function, however, they are located in peripheral nervous system and only myelinate one cell.

There are three distinct characteristics of connective tissue in the peripheral nervous system:

Endoneurium which is an individual nerve fiber and the connective tissue surrounding it.

Perineurium is a nerve fascicle and the the connective tissue surrounding it.

Epineurium which is the connective tissue that wraps around a nerve and also fills the spaces that lie between the nerve fascicles. 

http://confessionsofaleedsstudent.blogspot.com/2012/06/neuroanatomy.html

http://houseofmind.tumblr.com/post/729689108/ever-wonder-what-comprises-a-nerve-nerves-have

http://classroom.sdmesa.edu/eschmid/Chapter10-Zoo145.htm