 All right, we'll get started here. We've got a crowd. So what we're talking about today is the seventh nerve. I'm going to talk about anatomy. Russell's going to go over applied anatomy and clinical syndromes of the seventh nerve. And then Brian's going to review the fakeomatosis, which are a very high yield subject. So anatomy of the seventh nerve. So you can see the nuclei here in this picture represented here. And you can see its relation compared to the sixth nerve nucleus here. So the seventh nerve nucleus gets super nuclear input from the precentral gyrus for voluntary facial movement and actually gets some innervation as well from the basal ganglia, which controls involuntary blinking. It's important to remember that as far as super nuclear input from the precentral gyrus, the upper face gets bilateral innervation. So that's why you can see these brown and yellow lines here going to both nuclei. Upper face gets bilateral innervation, but the lower face is only contralateral. So that's why if there's some lesion that's affecting super nuclear input on the left side, you're going to get contralateral right just lower face paralysis. Here's another simple representation of some of the anatomy of the nuclei. So you can see the nucleus is ventral lateral to the sixth nerve. And the fascicle kind of wraps dorsally and medially and goes back around the sixth nerve nucleus and then comes anteriorly again for the nerve to exit right at the pontometallary junction. So you can certainly see how brainstem syndromes would affect the sixth and seventh nerve plus pyramidal tract and other structures in the area. This is a nice graphic off-stat DX that shows the seventh nerve kind of right as it exits the brainstem right at the pontometallary junction. It runs a little bit in the subarachnoid space. And then it enters the petrous part of the temporal bone, which is this kind of whole area here. And the opening that it enters is called the internal acoustic meatus. And then here's another view of the kind of brainstem, all the cranial nerves, as you can see, where the facial nerve exits in relation to the others. There's the sixth and the eighth. So it comes out right between those. And another view kind of showing that facial nerve going through the internal acoustic meatus to the petrous part of the temporal bone. While it's, I skipped ahead here, but while it's actually in the temporal bone, a few things happen. So kind of what's bundled in the seventh nerve is motor fibers, which is what we usually pay attention to. There's also parasympathetic fibers. Those originate at the superior salvatory nucleus in the brainstem. And those carry parasympathetic innovation to the lacrimal and submandibular and sublingual salivary glands. And then also in the temporal bone, the cortotimpinine nerve comes off from the facial nerve. And that is what carries actually taste information. So it's an afferent pathway for the anterior two-thirds of the tongue. And then the facial nerve, kind of the main branch or this motor branch, exits the skull out the stylo-mastoid foramen here. And then it branches into five branches that go to innervate all these muscles of the face. And there's a mnemonic I learned as an undergrad for remembering these. Does anyone know that? Tuzanzibar by motor car. So that stands for Tuzanzibar by motor car. So temporal branches, zygomatic, buccal, mandibular. And submandibular isn't part of that mnemonic. That just must be another little branch off the mandibular. And then the cervical branch was the last one there. So it kind of branches into these five kind of main branches in the parotid gland. So it kind of dissects right between two lobes of the parotid gland. So this is an axial T2-weighted MRI that shows the root exit zone of the seventh nerve, which is the more medial. And the eighth nerve is coming off just lateral to that. And so you can see that seventh nerve. You can trace that into the internal acoustic meadus into the temporal bone there. And this is a CT that I found on stat DX. This is, again, an axial cut through the left temporal bone. And again, you can see here the internal acoustic meadus or internal auditory canal. You'll hear it called both. And the seventh nerve kind of exiting right through that and diving towards that middle ear. You can see some of the ossicles there. So your first quiz question for the morning. Supernuclear lesion causing unilateral facial paralysis would be expected to cause. Everyone ready? Reese, what do you think? You would be correct. So remember that supernuclear input to the lower face is only contralateral. Upper face is bilateral. So supernuclear lesion, for example, on the right side is going to cause left-sided lower face paralysis. But the left forehead or upper face still has innervation from the left precentral gyrus.