Myelin sheath is a sleeve of fatty tissue aimed to protect nerve cells. Thus, the main function of the myelin is to shield fibers that are “the long threadlike part of a nerve cell” (Smith, 2019, para. 4). This myelin sheath has an important role in transmitting nerve impulses, allowing them to spread quickly and efficiently through the nerve cells. If a person has some problems with the myelin, this process of transmission may be slowed down. Consequently, such diseases as multiple sclerosis may occur (Smith, 2019). The damage of the myelin sheath leads to such signs and symptoms that Jacinda is experiencing because the nerves are left unprotected and cannot perform their function properly. Thus, the role of the nerves is to transmit signals from the brain to other body parts. However, if the nerve is unprotected or damaged, it will send wrong messages, and a person will feel fatigued, lose balance, lack concentration, and have other symptoms (Dangond, 2019).
Myelin sheath is present in the central and peripheral nervous systems. Its membranes are part of the Schwann cells in the peripheral system and the oligodendroglial cells in the central nervous system (Salzer & Zalc, 2016). Despite its origin in these two parts of the nervous system, multiple sclerosis affects only the central nervous system. The immune cells caused by the disease affect the brain and spinal cord, but the peripheral nerves remain untouched. It happens because the peripheral nerves use Schwann cells, which can regenerate. If the peripheral nervous system was damaged, it would revive, and its cells would re-grow. In contrast, the central nervous system cannot restore, and if its cells are damaged, scars will occur there, decreasing the nerve signals.
Dangond, F. (2019). Myelin sheath damage and multiple sclerosis (MS). Emedicinehealth.
Salzer, J.L., & Zalc, B. (2016). Myelination. Current Biology, 26(20), 971-975.
Smith, M. (2019). What is a myelin sheath? WebMd.