 Now we're going to do the mesencephalon. The mesencephalon, I'm going to pull on, is actually part of your brainstem, so we can see the structures that we're going to learn as part of the mesencephalon are visible in this little brainstem view. Remember that the superior part is not mesencephalon. That's actually the thalamus, that's coming from the diencephalon. But there's a structure that you can see here called the cerebral peduncles, and that is basically the cerebral peduncles connect to the thalamus and are actually kind of holding, or they're connected to the other two structures that we're going to learn. So the cerebral peduncles are part of the mesencephalon. In addition, we have two, well, actually it looks like there's four of them. There are little bumps on the dorsal aspect of the, I don't know if you guys can see, I'm going to undo that one because I kind of covered it over. Let's see if yellow works. Ah, nice. See this little, how these guys look like a little bee. Oh, you can't see that at all, but you get the idea. This little bee-shaped structure, and it is a posterior or dorsal structure in the brain. Right here is my cerebral peduncle. So that is my cerebral peduncle. And again, up here is my thalamus, same with this right here. Okay, are you cool? Are you kind of oriented to both my brain stem and my half head? These guys, the cerebral peduncles are just holding stuff up. So, and of course, does anything just hold anything up in the brain? No, there are tracks of neurons traveling through these structures and we'll call it good at that. These guys, number one and number two, these guys are interesting. So all told, together they make up a structure called the tectoplate. And your lab, of course, does not call it the tectoplate. Your lab calls it the corpore quadragemina. Quadragemina. We're going to change it to be tectoplate. The tectoplate consists of ultimately four, one, two, three, four structures. It contains superior, superior colliculi, colliculi, and who? ZZ, inferior colliculi. So there are two inferior colliculi and two superior colliculi. Okay, so here's the thing about these guys. These guys are awesome. They are reflex integrators. They receive information. The superior colliculus receives information from the eyes and the inferior colliculus receives information from the, I need a new color, from the ears. Here's the scoop. The information from the eyes goes to the superior colliculi. If the information, like there's a specific, like targeted pattern of this information, if it matches that pattern of kind of a peripheral, dangerous view, vision, like a spider crawling down or falling down from the ceiling or a big, dark shape coming at you from the periphery, like there, you can imagine those things that startle you if you catch sight of them in your periphery. So much information, we're just like, dude, we don't even want to start paying attention to all the sensory information coming in. We don't want to take the time to send something like a spider dropping down to the thalamus to have it evaluated. We want to be able to have a response immediately. So if the information is like that kind of peripheral, scary sensory information, the superior colliculus processes that and initiates a response, a motor response that involves turning your head and preparing to run away. So if there comes a thing in the periphery, you turn your head and you like rally, you get a surge of adrenaline, you prime yourself to run or to fight, you respond quickly and immediately without even thinking about it. What kind of response, what kind of stimulus are you responding to in the inferior colliculus? A sound, a loud sound like somebody drops some books, a car backfires, you hear a gunshot, a firework goes off. That sort of loud sound that startles you, you turn, you jump, that's coordinated by the inferior colliculi. How cool is that? Dude, this is so, it's so interesting to see where this information goes and then how the response is generated and it's happening in brain structures. Okay, NET and Cephalon is next.