a layer of myelin encasing (and insulating) the axons of medullated nerve fibers
双语例句
And wide gaps appeared between axon and myelin sheath, and between layers of myelin shea. 可见轴突与髓鞘间及髓鞘板层间形成宽大的裂隙。
In multiple sclerosis, the immune system launches an attack against the myelin sheath surrounding nerve cells, causing them to misfire. 在多发性硬化症中，免疫系统会攻击神经细胞周围的髓鞘，使其受损。
