上接“颞骨解剖(后颅窝部分)与桥小脑角区---Rhoton解剖视频学习笔记系列（上）”，欢迎阅读。
▼我们进而磨除内听道后壁。磨除内听道时往往需牺牲弓状下动脉，其盲端位于骨质内。
We drill off the meatus. To drill off the meatus you usually have to sacrifice the subarcuate artery, but it ends blindly in bone.
▼大约半数病例中，小脑前下动脉可呈襻状深入内听道口内。
In about half the cases the AICA will loop into the porus.
▼我们打开硬膜后，有时小脑前下动脉的血管襻甚至可进入内听道全程直至内听道底。
The...sometimes the AICA can loop all the way to the fundus.
▼这是前庭蜗神经
And here we've opened the dura we see VIII,
▼面神经
VII
▼中间神经的纤维束
and rootlets of intermedius.
▼我们再从后方看内听道内部，这是Bill棒
And here we're looking in from the back, and this is.. Bill's bar,
▼这是前庭上神经
superior vestibular,
▼这是前庭下神经
inferior vestibular,
▼这是蜗神经
cochlear,
▼这是面神经
facial nerve
▼这是中间神经
intermedius
▼当我们向外侧磨至 内听道口（下图）时，如果病变侵及前庭或半规管，且听力已丧失，我们可以向外侧磨至前庭。
So, now if you drill lateral to the porus of the meatus, you can..if the pathology goes into the vestibule or the canals and hearing is lost, you can drill all the way lateral into the vestibule.
▼这是弓状隆起。
And what is this? What is that prominence? Arcuate.
▼这是位于中颅窝的 上半规管。
And what canal is that? Superior.the canal of the middle fossa.
▼这是位于后颅窝的后半规管。
And this is...The canal of the posterior fossa, the posterior canal,
▼磨除这里将进入 总骨脚，它由 上半规管后脚 与 后半规管上脚 合成。
What did I drill into here? Common crus, the junction of the back end of the superior canal and the up end of the posterior canal.
▼我们也可打开 内淋巴囊（endolymphatic sac 下图）。
you can get into the...endolymphatic sac.
▼在内听道后方可见这个裂隙（下图），位于硬膜间。很多人会用医用橡胶堵塞内淋巴囊。
Here we see the hiatus that it sits in the dura on the back of the meatus.Someone are...a lot of you are gonna get a piece of rubber dam into the endolymphatic sac.
▼乙状窦（下图）下行，随后转而向上
Sigmoid comes down,and then what turns up
▼位于迷路下方的结构是 颈静脉球
under the labyrinth in the infralabyrinthine position? The jugular bulb sits here.
▼这里显示的是内淋巴囊的裂隙，其位于硬膜间
So that, here we see the hiatus of the endolymphatic sac. It sits in the dura,
▼内淋巴囊由乙状窦钩形包绕。
here in the hook of the sigmoid.
▼在暴露时，你可感觉到内淋巴囊，触碰此处的硬膜，会觉得其质地较柔软。
When you expose if you...wait to avoid it, while you can feel the endolymphatic sac in this area. The dura of...you feel through the dura, the dura is gonna get a little softer.
▼磨开位于迷路下方的这个区域，即可见颈静脉球位于迷路下方。
And then, this area under the labyrinth, if you drill this out, you see the jugular bulb here in the infralabyrinthine position.
▼充分显露颈静脉球，会发现其有时甚至可突入内听道后唇。
So that if we've exposed the jugular bulb here, it can even extend into the posterior lip of the meatus.
▼这是前庭蜗神经、蜗神经、面神经。
And this is the...this is VIII, the vestibular nerves. What nerve? Cochlear, facial.
▼这是半规管。
And, the canals are here.
▼在内听道底（下图）下方，前庭向前与耳蜗相沟通
And below the fundus of the meatus,the vestibule opens into the cochlea that sits here,
▼下图示耳蜗位置
▼耳蜗位于耳蜗三角内。与颈内动脉岩骨段的侧方毗邻。
adjacent this lateral bend of the petrous carotid. And it sits in that cochlear angle.
▼现在我们磨除了迷路（下图），前庭开口于内听道底下方，与耳蜗沟通。
So here we've drilled out the labyrinth. And the vestibule opens below the fundus into the cochlea.
▼下图示 内听道底
▼下图示 耳蜗
▼这是面神经
And this is going to be facial,
▼Bill棒
Bill's bar
▼前庭上神经
superior vestibular,
▼前庭下神经
inferior vestibular
▼这是前庭下神经的单孔支，其支配后半规管的壶腹。
and this is the singular branch of the inferior vestibular that innervates the ampulla of the posterior canal. ampulla [æm'pʊlə] 壶腹
▼前庭上神经 支配 上半规管 和 外侧半规管 的 壶腹。
And what canals does the superior innervate? The superior and lateral canal ampulla.
▼这是卵圆窗，镫骨位于此处。
And this is the...oval window in which the stapes sits.
▼这是右侧内听道底的骨性开口，下图是 Bill棒
So, you're looking at the fundus of the right meatus, Bill's bar,
▼水平嵴
transverse crest
▼面神经
facial
▼前庭上神经
superior vestibular
▼前庭下神经
inferior vestibular
▼蜗神经
cochlear
▼这是 单孔（singular foramen），其容纳支配后半规管壶腹的前庭下神经的单孔支。
singular foramen for the branch of the inferior vestibular that goes to the posterior canal ampulla.
