0:00

Let's successfully isolate in the axial projection,

0:04

the central sulcus of Rolando.

0:06

Let's start out by turning the brain

0:09

into a little bit of a map.

0:11

We're going to bifurcate the brain

0:13

right down the center,

0:15

along the falx,

0:17

and we'll call this 12 o'clock.

0:18

We'll call this 6 o'clock.

0:20

And then, at the level of the widest biparietal diameter,

0:24

we'll have 9 o'clock and 3 o'clock.

0:27

So now, let's keep that in our mind's eye.

0:31

We've got a sulcus right here,

0:33

which represents the superior frontal sulcus.

0:35

Let's follow the superior frontal sulcus back,

0:38

and we follow it into

0:41

all the way up high,

0:42

this is part of the superior frontal sulcus,

0:44

the precentral sulcus.

0:46

So if we've got the precentral sulcus,

0:49

we know that's going to be the superior frontal gyrus,

0:52

middle frontal gyrus, precentral sulcus,

0:55

precentral gyrus,

0:58

central sulcus of Rolando,

1:00

the precentral gyrus,

1:02

bigger than the postcentral gyrus.

1:05

Behind that is the postcentral sulcus.

1:09

Now, we said before,

1:10

the postcentral sulcus is the upswing

1:14

of the intraparietal arcuate-shaped sulcus.

1:18

It divides the brain into a superior parietal lobule,

1:22

here,

1:23

and an inferior parietal lobule,

1:25

here.

1:25

In the inferior parietal lobule,

1:27

you have the marginal gyrus and the angular gyrus.

1:30

So, let's summarize one more time.

1:33

The central sulcus of Rolando can be isolated by finding

1:39

the upswing, superiorly, of the superior frontal sulcus

1:44

into the precentral sulcus.

1:46

From there, it's easy.

1:47

Precentral gyrus, central sulcus, postcentral gyrus.

1:52

If you are a disbeliever or skeptical,

1:55

we spent many vignettes isolating the central sulcus

1:59

of Rolando and the sagittal projection.

2:01

There it is.

2:02

And it is consistent with our model.

2:06

There's our precentral sulcus.

2:07

There's our central sulcus.

2:09

You can see they cross-reference very nicely.

2:12

Isolating the superior frontal sulcus,

2:15

following into the precentral sulcus allows you to locate

2:20

the central sulcus of Rolando.