and these are the specific objects which are followed in the College of

Medicine, Al Jouf University. The first object is - Describe fasciae of the neck

and give their importance.

The second one is enumerate the structures in the anterior median plane of

the neck from above downwards. Third is, mention the actions and nerve

supply of sternocleidomastoid muscle, mention its relations and clinical

importance. Fourth is outline the triangles of the neck and list the contents of

each. Fifth is identify the super hyoid as well as the infrahyoid muscles and give

their actions and nerve supply. So these are some of the objectives which we'll

discuss one by one. To begin with - if you see the neck, neck is a very important

structure through which the lower part of the body will be in connection with

the head and neck. So a lot of structures will be entering from the, the

lower part from the thoracic region to the head and neck and many structures will

be descending downwards from the head and neck into the thoracic region and

this connection is very important here and this is confined to a very small

area called as the neck. Before we discuss about the neck itself will be discussing

em when we reflect the skin and superficial fascia, there is a very

important fascia, deep fascia called as the deep cervical fascia of the neck which is also

called as Fascia Colli. This the fascia which covers all the structures of the neck

and give us an additional support as well as covering so to defy it is a

facial which invests the muscles of the neck and fills up the

interval between muscles, vessels and cervical

viscera. So it's a fascia which invests the muscles of the neck so it covers totally

the muscles of the neck, gives protection to that, gives an additional support and

fills the interval between muscles, vessels & cervical viscera. So it covers

the structure separately the vessels and cervical viscera which are there like the

trachea itself, the esophagus, the thyroid gland. All these are covered by a special

facial which is called as the deep cervical facial of the neck. It has three layers or three

parts, one is called at the investing layer of the deep cervical fascia which is

the outermost covering. So if you see here in this picture this is how it

looks like to be more precise will go to the next picture here if you can see

here this is the cross section of the neck seen from above and you can see

here the the blue colored line, just below the skin and the platysma muscle here

there is a deep fascia, this is .. this blue line is called as investing layer

of deep cervical fascia. It is covering the whole of the neck as well as it is

giving extra support as well as covering the muscles here, both in the

anterior part as well as the posterior part. Here if you see the sternocleidomastoid

muscle, behind it is the trapezius muscle. So it covers on either side of these

muscles

Ok, so this fascia which is outer most of the three fascias, which covers the

whole of the neck. This is the investing layer of of deep cervical fascia. The

second fascia is called as the pre-tracheal fascia which is in front of the

trachea, so that's why it is called as pre-tracheal, it can be much more clearly

seen in this picture the cross-section where it is around the trachea, this is the

trachea here and here is the esophagus and these are the two lobess of the

thyroid gland and around that there is a fascia which is covering, this is called

as the pre-tracheal fascia, because it is in front

of the trachea so it is called as pre, pre means front. So pre-tracheal

fascia which covers the, not only in the front of the trachea but also on sides as well

behind, not only the trachea itself but also the thryoid glands, esophagus and other

structures. Then the third fascia which is there which is around the vertebras is called

as the pre-vertebral because it is in front of the vertebras. In this picture, if you

see here these are the vertebras, this is the spinal cord and in front of that you

can see that is a fascia which is called as the prevertebral fascia. To be more precise

in this picture is much more clear. Here you can see the the vertebral column and

this is the spinal cord inside and around that there are important muscles

surrounding this vertebral column itself and all the whole of this

structures, the muscles, the vertebra itself, the spine cord, everything is covered by a

additional fascia around all these structures and this is called as the pre

vertebral fascia. So its mentioned here the pre-vertebral, this pink line this is

the pre-vertebral fascia. This orange line this is the pre-tracheal fascia and

outermost is the, of the three fascias

this is the investing layer of the deep cervical fascia. These are the fascias which

are around the neck and covering very important structures in the neck. Along with

that there is an additional fascia which covers some very important structures

especially if you can see here, this is the fascia and it covers very important

such as like the common carotid artery. So that's why it is called carotid sheath

because it covers the common carotid artery as well as its

terminal branches - the external and internal carotid arteries, especially the internal carotid.

Then this is the internal jugular vein and here is the vagus nerve. There are

three important structures within the carotid sheath, there is a common character

and its branches, terminal branches. This is the internal jugular vein and the

vagus nerve. All these three structures

are covered by a special covering, this is called as the carotid sheath. This is also

part of the deep cervical fascia. So all these fascia are the part of the deep cervical

fascia of the neck which is also called the Fascia Colli. So these fasciae will

divide the whole of neck into compartments, one is called the visceral

compartment, Viscera means the organs like the pretracheal as well as the

prevertebral fascia where there are important structures like the trachea, esophagus,

thyroid gland and other structures so because these fasciae... this part of the

fascia will be covering important structures there, the organs (visceras) so

that's why it is called as the pre..... this is called the visceral compartment.

So this is a visceral compartment where the importance visceras like esophagus, trachea

thyroid gland and here the vertebral column itself, the spinal cord, the

muscles. So all these, the pre-vertebral and pre-tracheal fascia will be

called as visceral compartment. There is also a very important component is called

as the Neuro-vasacular compartment. Neuro means nerves and the vascular means vessels the

arteries and the veins. So this is in case in case of the carotid sheath where it is covering

very important neurovascular components neuro is the nerve i.e., is the Vagus nerve

here and the vascular that is the artery and vein, the common carotid artery as well

as the internal jugular vein. All these structures are covered by a separate

part of the deep cervical fascia. So this will divide this into a separate

neuro-vascular compartment.

Ok, so this is called as the neuro-vascular compartment inside which the carotid

sheath where the internet carotid artery, the internal jugular vein and the vagus nerve are

present. Why there should be fascia?

So some of the important functions of the fascia of the neck have been mentioned here

first of all it acts as a covering and also as a protective barrier, after the

skin

this will act as the second layer of defensive mechanism for any

kind of external attack by the bacteria, viruses or anything like that. So it acts

as a

protective barrier, as well as, it acts as a the covering to all the structures in

the neck. There are important structures in the neck, so it has to be covered by

extra structure. So this is called as the .... this is covering of the neck as well as also

it acts as a protective barrier. It gives passage to very important structures as

I said like the nerves and arteries. If you can see here, it is getting passage from

the artery like the common carotid artery it is passing from the thorax

and it is going into the, the head and neck part and it supplies, it gives the

arteries, the branches. the two terminal branches, the external carotid artery

as well as the internet carotid artery. The internal carotid artery will be one of the

two important arteries which will supply the brain and the external carotid

artery will be supplying all the structures in the neck as well as the

face. So these are very important structures which are passing from, from

the thorax into the head & neck part. Also the vein, the internal jugular vein is

draining the head and neck and face and brain into back into the the thoracic

region, as well as the vagus nerve which is one of the cranial nerve which is

coming from the brain and it supplies very important structures. It act as a

component of the autonomic nervous system and it will be supplying not only

the heart, the lungs. the GIT, many structures. So this fascia will be a

very important.

It gives passage for many, very important structures to move upwards and

downwards smoothly without any hindrance.

The third thing, important feature, feature of this importance of this

fascia is, if there is in case of any infection, then the pus will be confined

to that area. If there is some infection here in this component or here somewhere

so it will be confined to that party, doesn't spread to the all of the neck. So

again as I said there are very important structures in the neck. So if there is

any infection so it should not spread to other parts, so

because of this fascia, the infections and the pus collection will be confined

to that particular area and it prevents the spreading of infection from one part

to the other side. If there is any infection here, it will not go to the

other side or to here or somewhere else. So this will, this fascia will acts

as a barrier for the spread of any infection to any other parts. Fourth is, it gives

additional support to the muscles and other structures. If you see here the

sternocleidomastoid or trapezius, they have their own origin and insertion, ie., the

actually support the support of that muscle but additionally this fascia

will, if you can see here it is totally covered by this fascia. This fascia

splits into two, the anterior layer and posterior layer and it totally covers this

muscle. This is giving an additional support to these muscles and other

structures. So here also can see the carotid sheath is covering the

structures, the arteries and the vein and nerve and giving an additional

support. So this fascia will also acts as a very important structure

which will give additional support to muscles and other structures. So these are some of

the, the importance of having a fascia in the neck. One is it acts as a covering

second it protects from... acts as a protective barrier and protects from the

infection like any bacteria, virus or something like that. It gives important

passage for the structures, important structures like the nerves, arteries and veins and if

there is any infection it will be confined to that area and prevent the

spread of infection and the puss to other parts and fourthly it gives

additional support to muscles and other structures. So these are some of the

importance of the fascia in the neck

ok