Individual cells in the nervous system are called neurons. Some neurons have myelin sheaths around their axons. Here's a typical illustration of a myelinated neuron.
You said “myelin sheaths and axons”: are you talking about nerves and tendons?
No. Here is a link to an excellent glossary of terms commonly used when discussing MS.
http://www.geocities.com/HotSprings/3468/gloss.html
Hope that helps.
Individual cells in the nervous system are called neurons. Some neurons have myelin sheaths around their axons. Here's a typical illustration of a myelinated neuron.