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Let's talk about the optic nerve and pathway.

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Cranial nerve number two,

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responsible for vision,

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an all-important nerve.

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We start out very simply anteriorly

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where we have retinal cells,

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which we'll define a little bit later in some detail.

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And then we go right into the optic nerve

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and we'll call this the intraorbital portion

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of the optic nerve.

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And now, we'll scroll a little bit further back

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to get to the foraminal portion of the nerve.

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You can just barely see it right there on both sides.

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So foraminal optic nerve and then you want to

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get to the prechiasmatic optic nerve here,

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then the optic chiasm and then the optic tract with

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the pituitary stalk and infundibulum

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and median eminence located there.

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So let's go back down to the foraminal nerve and

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follow it forward again as the intraorbital portion

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of the optic nerve and then back to the retina.

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Now let's go back to the optic chiasm.

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The optic chiasm has this funny little hockey stick

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shape and these structures continue back to the

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lateral geniculate nuclei where

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they will form a synapse.

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There's also a synapse in the region of the

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superior colliculus that they give off.

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So you have one synapse here,

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one synapse here and then you'll have a continuation

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from the lateral geniculate nucleus as the optic

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radiation. We're in the temporal zone region now,

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so we'll call this the temporal knee or temporal

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portion of the optic radiation.

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And it kind of makes this little notch right here and

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then makes a turn posteriorly

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towards the occipital lobe.

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And many of these fibers are going to arborize

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around the calcarine fissure,

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which is right here and here's the corresponding

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calcarine fissure right there.

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So I'm going to draw over the calcarine fissure here,

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the parieto-occipital sulcus separating the occipital

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lobe or cuneus from the precuneus.

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So I'm going to draw.

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Draw it all in together.

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So you've got it in one fell swoop.

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You've got the retina here.

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Then you've got the optic nerve.

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Then you've got the intracanalicular

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foraminal optic nerve,

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then the prechiasmatic portion of the optic nerve.

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Then you hit the chiasm, which we have right here.

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Then you've got the optic tract that goes back.

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The optic tract is going to have a synapse with the

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lateral geniculate nucleus and the superior colliculus.

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It's going to continue on as the optic radiation.

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There's going to be an upper and a lower

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portion of the optic radiation.

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I've drawn in the temporal portion or temporal

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knee of the optic radiation.

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This area is called the sagittal

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stria of the optic radiation.

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And then it's going to arborize onto the occipital

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lobe, right around the calcarine sulcus on both sides.

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So that's a quick intro to the visual pathway.

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Pomeranz out.