I’m in neuroscience. For the next few minutes I am going to try to blog everything this old fucker up on the podium says.
Here I go…
How about pupillary light?
Yeah, see, it’s the brainstem huh?
Mylencephalon involved to rostral colliculus..
Now, what if we have a facial nerve lesion?
Gonna work?
Not on the side that’s got the lesion, but yeah on the other.
[Fuck I can't keep up with this guy.]
So now the lesion has to be in the cerebellum, not the cortex.
Okay, so keep in mind, these are the things we want to do.
This is mesencephalon, not the cortex.
See the rostral colliculus? It’s going to do tectorecticular tract – tecum. It’s part of the visual tracking.
If he smells your hand he’s gonna follow you where you move it.
(He just told a story about visual tracking and laser pointers back in the 80’s…)
So what’s the deal about the menace response? You’ve just gotta memorize every spot along the way.
Now let’s deal with pupillary light reflex.
We’ve got two parts to that – a direct, the eye that you’re shining the light in. Source of light ot the eye.
When one pupil comes down the other should be coming down.
There should be consensual miosis.
Pupil constriction is parasympathetic innvervation — how’s that work?
Parasympathetic oculumotor nucleus in the preganglionic axon, neuron numberone. Axons are in cranial nerve three.
They synapse to the ciliary ganglion. THis is neuron number two.
This innvervates the constrictor pupilla muscle… then boom, miosis.
So, comes in optic track, down to pretectalm synapses, crosses over and goes out…
Also coming up here because of the optic chisma.. so two crosses.
So a lesion right here, no one constricts. Lesion here, one constricts.
So this guy goes here, he whams in.
This guy, in here, he whams in too.
So these guys go bilaterraly, go up in, bingo, constricture.
We’ll go over dilation in a minute — that’s part of sympathetic.
Primates and carnivores … rapid pupil constriction.
Ruminants and horses are… you flip the lights, you go out and you get a sandwich, you come back and they’re still workin’ on it.
They’re slow as snails.
Damn deer.
I knew my number was coming up, saw four dead deer on the side of the road…
Anyhow, that’s my aside, you don’t need to remember that.

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