bulla是什么意思

用法例句

The experimental group underwent an incision inferior to the pinna,and the cochleas were destoried with a drill through the bulla bilaterally.

实验组采用耳后径路开放听泡,用微型钻在耳蜗表面钻孔损毁双侧耳蜗结构;对照组仅做耳后切口不破坏耳蜗结构。