hi let's talk about the arteries of the posterior neck so systemic circulation
begins in the aorta specifically the ascending aorta which is exiting blood
out of the left ventricle that ascending aorta feeds into the arch of the aorta
this arch of the aorta has three major branches there's the brachiocephalic trunk then the
left common carotid artery and then they left subclavian artery the brachiocephalic trunk has
two major branches the right subclavian artery and the right common carotid artery so if you
notice here there are two subclavian arteries and two common carotid arteries the subclavian
arteries predominantly serve blood to the upper limbs but they also serve blood to the thoracic
wall as well as the neck the common carotid arteries are going to bifurcate into internal
and external carotid arteries the internal carotid arteries will predominantly serve
the contents of the cranial cavity as well as a portion of the face whereas the external carotid
arteries will predominantly serve the neck and face and superficial parts of the head when we
look at the subclavian arteries we see that they can theoretically be divisible into three parts
these three parts are named relevant to the anterior scalene muscle so here we can see the
anterior scalene muscle descending down laterally of the neck and inserting into the first rib so
everything which is medial to the anterior scalene muscle will be the first part of the subclavian
artery anything which is be high the anterior scalene muscle will be the second part of the
subclavian artery and everything lateral to the lateral margin of the anterior scalene muscle
will be the third part of the subclavian artery and the subclavian artery is going to end at
approximately the lateral margin of the first rib so everything beyond will be the axillary artery
and then eventually that axillary artery will be contiguous with the brachial artery but let's look
at the branches of each part of the subclavian artery so the first part of the subclavian artery
everything which is medial to the medial edge of the anterior scalene artery there are three
major branches quite a large branch heading superiorly and medially here is the vertebral
artery that vertebral artery is heading towards the transverse foramina of cervical vertebra
c6 through C 1 so it will be protected by the by the bone around those foramina and the vertebral
artery will send off branches to the spinal cord and meninges and eventually it will head through
the foramen magnum of the skull where it meets its counterpart to form the basilar artery and
thus supply the posterior portions of the brain with blood the other major artery which supplies
the brain with blood is the internal carotid and we'll see in subsequent sessions how vertebral
artery plus internal carotid artery supplies the cranial cavity with the next major branch
of the first part of the subclavian artery is the internal thoracic artery that internal thoracic
artery is going to supply the anterior and lateral walls of the thorax with blood as well as parts of
the wall of the abdomen with blood as well the third branch is more topical to what we'll be
discussing in this course and that is the thyrocervical trunk so the thyro, thryoid, the cervical, neck,
trunk and it's going to have four branches so the thyroid cervical trunk main branches are
and we'll just go counterclockwise here the inferior thyroid artery the inferior thyroid
artery is heading medially and superiorly towards the thyroid gland which we can see here in the
parathyroid glands and it's going to have a branch that we'll see later called the inferior laryngeal
artery so to be explored later the next branch is the a sending cervical artery the a sending
cervical artery is going to supply some of the deep neck muscles such as the scalene muscles so
here's the anterior scalene muscle with blood our next branch is the transverse cervical artery that
transverse cervical artery is going to be the blood supply to the trapezius muscle and from
time to time that transverse cervical artery may also give rise to the dorsal scapular artery that
dorsal scapular artery is typically a branch of the third part of the subclavian artery but
it may arise from the transverse cervical artery and then finally we have the suprascapular artery
that suprascapular artery Supra above scapular the scapula is going to head around and then go
through the suprascapular notch and it's going to serve two of our rotator cuff muscles the
Supra and infra spinatus but honest muscles with blood here we have the anterior scalene muscle removed
from the first rib in reflected upwards and this is going to allow us to see that second part of
the subclavian artery and it's only branch the costocervical trunk so Costo would be a
rib cervical neck so this trunk is going to supply two regions with blood there are two
major branches there is the deep cervical artery that deep cervical artery will supply some of our
deep neck muscles with blood and then the highest or supreme intercostal artery is going to supply
the first and the second intercostal spaces those are the spaces between the ribs with blood and we
can see that first intercostal space there and last but not least we have our dorsal scapular
artery our dorsal scapular artery is going to run over and then medial to the scapula and it's
going to supply the levator scapulae with blood as well as the rhomboid muscles minor and major
with blood sometimes as we've said before this dorsal scapular artery is actually coming off of
the transverse cervical artery and so anything after that lateral margin of the first rib we
go from the third part of the subclavian artery to the axillary artery then axillary artery is
going to run through the axilla or the axillary region colloquially the armpit and it's going
to be an important artery for the naming of parts of the brachial plexus as we'll discuss
so we've discussed the major vessels coming off of the arch of the aorta and specifically
the parts of the subclavian artery and their branches thank you very much for your time