 
<translate> Myelin bụ ihe nwere abụba (abụba) nke na-eme n'ime sistemụ akwara etiti (CNS) site na mkpụrụ ndụ glial a na-akpọ oligodendrocytes, na sistemụ akwara mpụga (PNS) site na mkpụrụ ndụ Schwann. Myelin na-eme ka axons nke mkpụrụ ndụ akwara dị iche iji mee ka ọsọ ọsọ nke ozi (nke a na-etinye dị ka mgbaàmà eletrik) na-esi n'otu mkpụrụ ndụ akwara gaa na nke ọzọ (dị ka CNS) ma ọ bụ, dịka ọmụmaatụ, site n'otu mkpụrụ ndụ akwara gaa na akwara (dị ka PNS). A pụrụ iji axon nke nwere myelin tụnyere waya eletrik (axon) nke nwere ihe na-ekpuchi ya (myelin) gburugburu ya. Otú ọ dị, n'adịghị ka plastik e ji ekpuchi waya eletrik, myelin adịghị emepụta otu mkpuchi ogologo n'ogologo axon ahụ dum. Kama nke ahụ, mkpuchi myelin ọ bụla na-eme ka axon dị n'otu akụkụ, na, n'ozuzu, axon ọ bụla nwere ọtụtụ akụkụ myelinated ogologo nkewapụrụ site na ibe ha site na obere oghere. A na-ekepụta akwa myelin nke ọ bụla site na mkpuchi mkpuchi nke oligodendrocyte ma ọ bụ usoro Schwann cell gburugburu axon.  Zaa ajụjụ a: myelin sheath nke na-ekpuchi ọtụtụ cns axons ka emepụtara? Ka anyị buru ụzọ mee ka uche anyị dịrị n'ihe anyị na-eme: <eng> Myelin is a lipid-rich (fatty) substance formed in the central nervous system (CNS) by glial cells called oligodendrocytes, and in the peripheral nervous system (PNS) by Schwann cells. Myelin insulates nerve cell axons to increase the speed at which information (encoded as an electrical signal) travels from one nerve cell body to another (as in the CNS) or, for example, from a nerve cell body to a muscle (as in the PNS). The myelinated axon can be likened to an electrical wire (the axon) with insulating material (myelin) around it. However, unlike the plastic covering on an electrical wire, myelin does not form a single long sheath over the entire length of the axon. Rather, each myelin sheath insulates the axon over a single section and, in general, each axon comprises multiple long myelinated sections separated from each other by short gaps. Each myelin sheath is formed by the concentric wrapping of an oligodendrocyte or Schwann cell process around the axon.

Answer this question: the myelin sheath that covers many cns axons is formed by? Let's give stream of consciousness first: 