0:00

Let's finish our discussion of cranial nerve number two,

0:04

the optic nerve with a couple of pearls.

0:07

The contralateral nasal retinal projection,

0:11

from the lateral, projecting onto the medial

0:16

aspect of the retina.

0:17

So lateral projecting on medial retina,

0:20

is going to come down,

0:22

and is going to cross over the other side.

0:24

Same thing here,

0:25

projects onto the medial retina,

0:27

comes down and crosses in the optic

0:30

chiasm to the contralateral side.

0:32

In contrast,

0:34

the medial field is going to project onto the

0:38

lateral retina and it's going to

0:41

stay ipsilateral like. So.

0:48

Now, we also said that there are a number of

0:51

which we'll show you in a minute.

0:53

There is a knee or turn of the optic radiation.

0:57

There is an occipital or occipital.

0:59

Temporal and a temporal component of this turn,

1:02

where it will then project onto the Cuneus or

1:07

optic cortex. It'll happen on both sides.

1:10

Now I'm going to scroll up a little bit

1:14

to the level of the calcarine sulcus.

1:19

And at this level, we've got the calcarine cortex.

1:23

And I wanted to high light the synapse

1:26

positions a little bit higher,

1:28

which include the lateral geniculate nucleus,

1:31

which is going to sit right about here on both

1:34

sides. That's going to receive a synapse.

1:36

The superior colliculus,

1:38

that's going to receive a synapse.

1:40

And now we have one final third synapse to add to

1:43

our layering of anatomy for the visual pathway.

1:46

And that is the pulvinar right there.

1:50

So that concludes our discussion of the visual

1:53

pathway. So if we put it all together,

1:56

we've got the globes, we've got the retina,

1:58

we've got the optic Nerve.

2:00

We got the intracanalicular for raminal optic

2:03

nerve. We have the prechiasmatic nerve.

2:05

The optic chiasm a little infundibular recess

2:08

in the middle with a pituitary stalk,

2:11

the optic tracts moving posteriorly,

2:13

a synapse on the superior colliculus and

2:15

the lateral geniculate nucleus,

2:17

a synapse on the pulvinar and

2:19

then continuation back,

2:21

including something known as Meyer's loop that will

2:25

arborize onto the visual cortex in the region of

2:28

the calcarine sulcus which we see right here.

2:31

That concludes our discussion of the visual pathway.