單項選擇題以下關(guān)于脊神經(jīng)和神經(jīng)根結(jié)構(gòu)的描述錯誤的是()

A.脊神經(jīng)根覆蓋有神經(jīng)外膜
B.外周神經(jīng)覆有神經(jīng)外膜
C.脊神經(jīng)近脊神經(jīng)節(jié)處才有一薄層神經(jīng)外膜
D.脊神經(jīng)由神經(jīng)纖維和胞體組成
E.外周神經(jīng)只由神經(jīng)纖維組成