n.（拉丁语）骨髓； 变形： 复数：medullae 英英释义： medulla[ me'dʌlə ]n.a white fatty substance that forms a medullary sheath around the axis cylinder of some nerve fibers同义词：myelinmyelinelower or hindmost part of the brain; continuous with spinal cord; (`bulb' is an old te