Anatomy of Neck (Complete) …………. by Dr. Yusuf


Hi Students, today we will be studying about
the Anatomy of the Neck. This is Dr Yusuf 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 define, 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 platisma 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 pretracheal 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 vegas 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 pus 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.

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