Multiple sclerosis

Multiple sclerosis (MS) is a serious health condition that gets worse over time. In this disease, the body’s natural guard against illness (the immune system) damages fatty coverings called myelin sheaths around the nerve cells (neurons) in the central nervous system (CNS).^[1] The disease has different effects in different people, and can make people’s bodies, eyesight, speech, and minds work poorly.^[2] People with MS do not normally live as long as healthy people.^[1]

In healthy people, myelin sheaths help neurons work.^[3] Electric signals in neurons move quickly through long, narrow axons like electricity in a wire.^[3] The myelin is like the insulator around the wire that keeps the signal strong by keeping it from moving out of the wire before the end.^[3] In people with MS, infiltration of immune cells causes inflammation within the CNS resulting in the loss of the protective insulator, called "demyelination." The progressive loss of the myelin sheath, as well as the loss of myelin-producing cells, impair the ability of the body to regrow its myelin.^[2] Without the protective covering, the signals between neurons do not travel well.^[2] Because of this, the mind and body cannot work like they normally do.^[2]

1. ↑ ^{1.0 1.1} Compston, Alastair; Coles, Alasdair (Oct 25, 2008). "Multiple sclerosis". Lancet. 372 (9648): 1502–17. doi:10.1016/S0140-6736(08)61620-7. PMID 18970977. S2CID 195686659.
2. ↑ ^{2.0 2.1 2.2 2.3} Compston, Alastair; Coles, Alasdair (Apr 6, 2002). "Multiple sclerosis". Lancet. 359 (9313): 1221–31. doi:10.1016/S0140-6736(02)08220-X. PMID 11955556. S2CID 14207583.
3. ↑ ^{3.0 3.1 3.2} al.], Neil R. Carlson ... [et (2010). Psychology : the science of behavior (7th ed.). Boston: Allyn & Bacon. ISBN 978-0-205-54786-9.