Interactive Transcript
0:01
Outside of the globe,
0:02
we usually think about orbital anatomy
0:05
in three different spaces.
0:07
The intraconal space, with the cone representing the muscles,
0:12
the conal space of the muscles.
0:15
And then, we have the extraconal space.
0:18
And there is different pathology that occurs in each of these spaces.
0:23
So, let's start with the intraconal spaces, the space
0:27
inside the muscle cone. This includes orbital fat,
0:32
arteries and veins, and various nerves, which include the
0:36
optic nerve as the dominant nerve of the orbit.
0:39
The oculomotor cranial nerves, three, four, and six.
0:45
And then, there are also branches of the fifth cranial nerve.
0:49
In this diagram, we can analyze the orbit
0:52
in terms of the various spaces.
0:54
That space, which is within the muscle cone,
0:59
is the intraconal space.
1:00
We consider the muscles themselves
1:03
part of the conal space.
1:05
And this is seen both on the axial diagram to the
1:08
right and the coronal diagram to the left.
1:11
And we have our inferior rectus muscle,
1:15
our medial rectus muscle, lateral rectus muscle,
1:19
superior rectus muscle, superior oblique muscle.
1:22
And this muscle above the superior rectus
1:25
muscle is the levator palpebrae muscle.
1:28
Outside the muscle cone is the extraconal space.
1:32
And as you can see, this includes orbital fat and bone,
1:36
as well as, more medially,
1:38
the paranasal sinuses.
1:39
And the paranasal sinus,
1:41
which leads to the most orbital pathology,
1:45
is the ethmoid sinuses, seen here.
1:49
Superficially, we also have an extraconal space.
© 2024 MRI Online. All Rights Reserved.