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Mediastinum: Anatomy & Contents (preview) - Human Anatomy | Kenhub

if there's one thing we can say with

certainty about our bodies it's that

they're both organized and efficient in

their layout almost every structure in

our body big or small is

compartmentalized in one way or another

to ensure that everything stays where it

needs to be

one way which our body achieves this is

by the presence of defined spaces or

cavities for instance our cranial cavity

keeps our brain safely tucked in our

head and our abdominal cavity packs in

over seven meters of gut to absorb

anything worth taking from that burger

you had for lunch

our thoracic cavity is also an

interesting space with its bony cage

protecting your heart and lungs but

between our lungs is a special yet

somewhat anatomically complex region

whose name alone often rings horror to

anatomy students all over but don't fear

that's why we're here I assure you it's

safe to come out because today we're

going to master the anatomy of

the mediastinum so let's get down to

business and see what the fuss is all

about so we've established that the

mediastinum is located roughly on the

midline of our body between the pleural

cavities of the thorax

in our tutorial today we're going to be

looking at the anatomy of this space

with these two illustrations with both

right and left lateral views of the

thorax so let's take a moment to define

some of the anatomical boundaries of the

mediastinum as a whole anteriorly the

mediastinum is limited by the anterior

thoracic wall which is comprised of the

sternum as well as the costal cartilages

of the first two fifth ribs which you

can see here highlighted in green

the posterior boundary of the

mediastinum is marked by the vertebral

bodies of the superior thoracic

vertebrae knowing the anterior and

posterior borders of the mediastinum we

can now define the superior most border

of the mediastinum as the superior

thoracic aperture delineated by the

manubrium of the sternum following

around the superior border of the first

rib to the t1 vertebral body of course

laterally since the mediastinum is

located between the pleural sacs the

parietal pleura of each lung provides

the lateral border for each side of the

mediastinum and finally the inferior

boundary of the mediastinum is formed by

the respiratory diaphragm which you can

see just over here so to give our

borders a little bit more context let's

take an alternative look at the

mediastinum by looking at the diaphragm

from a superior perspective and heating

so he can get a better idea of the space

occupied by the mediastinum okay now

let's get into the nitty-gritty of what

the immediate einem is all about so as

typical and atomists we'd like to divide

things up into smaller divisions to make

it easier for us to explore and of

course the mediastinum is no different

so the mediastinum as a whole can be

subdivided into two major divisions and

firstly we have the superior mediastinum

which is found superior to an imaginary

line known as the thoracic plane

intersecting the sternal angle

anteriorly and the t45 intervertebral

discs posteriorly and of course if we

have a superior there must also be an

inferior mediastinum this video is not

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