Most neurons are insulated by a myelin sheath formed by cells (Schwann cells) surrounding the axons. Bundles of fibres from neurons held together by connective tissue form nerves.是什么意思_Most neurons are insulated by a myelin sheath formed by cells (Schwann cells) surrounding the axons. Bundles of fibres from neurons held together by connective tissue form nerves.在線翻譯_英語_讀音_用法_例句