Alright, next stop in this journey of the neck is to look at the cervical compartments. The cervical
compartments of which there are four are organized in a vertical direction. Let’s take a look
at the first compartment. Here, we’re looking at the visceral compartment right in through here.
It is surrounded by the yellow line which is a sheath. We’ll get to that sheath and its name here
shortly. But the visceral compartment contains the thyroid gland, see one lobe there and the opposite
lobe here. We also see in this view the trachea. Then lying posterior to the trachea, we have the
esophagus. Next, we have two vascular compartments. These are oriented
more laterally. So, we see one on the left side of the image here. We see the opposite one here
on the right side of the image. Each one of the vascular compartments contains a pair of vascular
structures. The one that we see out here more laterally oriented is the internal jugular vein.
Then the one situated more medially is your common carotid artery. That same relationship exists
on the left side of the image where we have the lateral most structure being your internal jugular
and then the medial structure being your common carotid. The fourth compartment is referred to
as the vertebral compartment. The vertebral compartment is containing structures that relate
or associated with this region of our anatomy. We can see various vertebral muscles that are
identified by these multiple leader lines. When we sum everything up, we can characterize
the cervical compartments as being the four Vs: one visceral, two vascular, which brings us to
three and then the fourth V would be the vertebral compartment. Next, we need to understand
the cervical fascia. When we look at the fascia of the neck, we are looking at fascia that is related
superficially and then we have fascia that is referred to as the deep cervical fascia.
The superficial fascia is identified in through here. This particular structure that’s a part of the
superficial fascia is the platysma muscle. Anterior to the sternocleidomastoid,
this superficial fascia would run posteriorly. Next, we have deep fascia. The deep fascia is
more complex and that it is divided into several distinct layers. So, the next sequence of slides
will allow us to explore these distinct layers of the deep fascia. Here is an image that depicts
in color the various deep fascial components. See some here in blue for example, the line in
magenta, line in yellow, line in purple. So let’s identify these various deep fascial layers.
The first is referred to as the investing deep fascial layer. This contains the
sternocleidomastoid and trapezius muscles. The deep fascia that’s investing is shown here
for example. We can see that this investing fascia at this point is splitting and
they’re continuing on a deep surface of the trapezius, as well as on its superficial surface.
In the posterior midline, it joins to form one layer. Then as you go to the opposite side,
that single investing fascial layer divides with one division going superficial to the trapezius
and again one going deep to the trapezius. As you come anteriorly, they join to form one investing
layer and then they separate around the sternocleidomastoid again forming a superficial
component or lamina as well as a deep lamina. The second deep fascial layer to identify
is known as the pretracheal fascia that is shown in yellow. This will surround the structures
that are found in the visceral compartment. So, the pretracheal fascia is surrounding your
thyroid gland, two lobes here, the trachea here in the center, and then posterior to the trachea,
the esophagus. Next, we want to understand the carotid sheath and the structures that are
contained within this deep fascial layer. Most of them are illustrated in the image here that we
see on the right. But if we take a look here, here is the carotid sheath on the left side
of the image, carotid sheath on the right side of the image. The two vascular structures that we see
here within the carotid sheath will be the internal jugular vein and your common carotid artery.
The carotid sheath does extend more superior to this view. It will surround or envelope
the internal carotid artery as well. Also, we have a nerve within the carotid sheath. This is a
substantial, fairly large nerve. It’s a cranial nerve. We see it here on the opposite side as well.
This is the cranial nerve X also known as your vagus nerve. Then the last structures that are
contained within the carotid sheath not shown here would represent the cervical lymph nodes.
If cancer spreads to these deep cervical nodes, these nodes would be enlarged and palpable.
As we continue looking at the deep fascial layers, here we can see that the prevertebral layer
right in through here, fairly extensive, it’s surrounding the vertebral compartment.
So that would include the vertebra in the region, the spinal cord within the vertebral canal.
And then more externally, we can see several different vertebral related muscles
that would be enclosed by the prevertebral deep fascial layer.