The answer would be the hardening of the myelin sheath. Multiple sclerosis is a chronic and inflammatory disease affecting the Central Nervous System and can cause a lot of symptoms like sensation changes, visual problems, severe fatigue and muscle weakness.
The disease is caused mainly because of the attack on the myelin sheath by own immune system.
Explanation:
The MS or multiple sclerosis refers to a possibly disabling disorder of central nervous system. In the condition, immune system fights against and destroys the myelin, that is, the protective sheath, which envelopes the nerve fibers. This causes problems of communications between the brain and the entire part of the body. Ultimately, the disease can result in deterioration or permanent destruction of the nerves.
4.4 Animal tissues (ESG6H) Animal cells with the same structure and function are grouped together to form tissues. There are four types of animal tissues: epithelial tissue, connective tissue, muscle tissue and nervous tissue.