So this is a tutorial on the organization of the neck.
I'm going to talk a little bit about the anatomical triangles of the neck, the anterior and posterior
triangles.
And then I'll go on to talk about the fascial compartments.
I'll also talk a little bit about the different structures that pass through the anatomical
triangles, but I'll go on to more detail on other tutorials on this.
So we're looking at an anterior view of the neck.
You can see this thin muscle here.
This is the platysma muscle.
This is contained in the superficial fascia of the neck.
So I'll get rid of these and show you the different triangles.
If I just zoom a little bit more, I got rid of the platysma muscle, which lies in the
superficial fascia and then you can see this big muscle here, which runs from the mastoid
process down to attach onto the sternum and also onto the clavicle.
So it's got two attachments, a sternal and a clavicular attachment, then it's also attached
to the mastoid process up here.
So this is the sternocleidomastoid muscle named because of its attachments.
The anterior triangle of the neck is defined by few boundaries -- the inferior border of
the mandible forms the superior border of the triangle, the midline forms the medial
border and the anterior border of the sternocleidomastoid muscle forms the lateral border of the triangle.
So the triangle is this here, the midline, inferior surface of the mandible.
So you've got the inferior surface of the mandible forming the superior border.
You've got the anterior border of the sternocleidomastoid forming the lateral border and the midline
of the neck which runs right down here forms the medial border.
So that's the anterior triangle of the neck.
So as you can see here, there are several structures which run in the anterior triangle
of the neck.
I won't go into huge detail on what these are, but I'll just quickly go through them.
You can see this bone here.
This is the hyoid bone.
This bone is important because it forms the attachment for many muscles which make up
the floor of the mouth and it provides attachments for the tongue muscles and it's involved in
swallowing.
So this is the hyoid bone here.
Muscles above it are called the suprahyoid muscles and these run in the anterior triangle.
And you've got these muscles below the hyoid bone, so these are the infrahyoid muscles.
These infrahyoid muscles are also called strap muscles because of their appearance.
I guess they look like a strap, so these are the strap muscles.
Below the strap muscles, we've got the thyroid gland.
We've got the larynx here and the trachea.
We've also got the parathyroid glands behind the thyroid.
And then also, you've got these vessels, which obviously run in the anterior triangle.
You've got the common carotid and its branches, so the external and internal carotid.
You've got the internal jugular vein running through the anterior triangle.
And then you've also got nerves.
So for instance, the vagus nerve and recurrent laryngeal nerves run through the anterior
triangle.
That's the anterior triangle.
Just to recap, it's formed by the anterior border of the sternocleidomastoid, the inferior
margin of the mandible and the midline of the neck.
So the posterior triangle lies just behind the anterior triangle.
It's formed by the posterior border of the sternocleidomastoid, the middle portion of
the clavicle and the anterior border of the trapezius muscle, this big muscle at the back
(the big, powerful muscle there).
The apex of the posterior triangle is this bit of occipital bone just behind the mastoid
process here.
You can see the triangle formed by the anterior margin of the trapezius, the middle portion
of the clavicle and then the posterior border of the sternocleidomastoid with its apex just
behind the mastoid process.
So again, the posterior triangle of the neck contains a lot of important structures.
I'm not going to go through all of them, but just a few so...