Let’s start with oral cavity and
obviously it is about the oesophagus
and the stomach. But let's start with the oral cavity.
We have got the oral cavity here. We can see
the tongue so food is coming in
this direction. While the teeth
are going to be chewing or breaking
down this food into ever
smaller portion. And we can see in the oral
cavity, this process of cutting and chewing,
this mechanical digestion
has started. It mixes with
saliva along with the
chemical digestion to start as well.
And then chewing... the process of swallowing
this food is passed into the pharynx
which we can see here.
Remember I said the trachea is anterior?
So here we got the neck
so we can see the trachea was anteriorly
and directly behind the trachea we see the
oesophagus which is running down in this
direction. So the food is converted
to this bolus which is swallowed into
the oesophagus via the pharynx.
It's then going to descend through
the thorax and pierces
the diaphragm. And for food to pass
down through this oesophagus.
The muscular walls of this
and peristalsis carries
that food inferiorly.
So here we have got an another view of the
oesophagus and its position within the thorax
ends. We can see anteriorly that
it’s impossible to see
the oesophagus with the stomach in position
and here we have highlighted in this anterior
view, the position of where the oesophagus would be.
If we look at the posterior
view, then we can see the diaphragm here.
We can see the outline of
the posterior aspect of the heart here,
sitting on the diaphragm.
Now we can see this large blood vessel
here, that is the aorta.
Now we can see running inferiorly down,
we have our oesophagus.
It is running directly behind the
posterior surface of the heart.
And then it's going to enter into
the abdomen by passing
through the diaphragm. And it passes through the
diaphragm, that we will
come to see, at the level of
the 10th thoracic vertebrae
we can see that here. If we just briefly
look at the blood supply to the
oseophagus, this really comes from the
esophageal branches directly from the aorta.
The aorta is running alongside the
oesophagus in the thorax and small
branches comes away from the aorta
to supply the oesophasgus which we can see
here. The oesophagus then pierces
through the diaphragm
that what I said it was the 10th thoracic
vertebral level and then it quickly
joins into the stomach,
junction and this occurs above the
11th thoracic vertebral level.
So we can see the oesophagus we have in the
throax penetrating the diaphragm into the
abdomen to then be continuous
with the stomach.
So here we can see that in more detail.
We can see we have the diaphragm here, we have got
slightly elevated diaphragm right down
the slightly elevated on the right
because of the liver and we can
see that its going through the diaphragm
we have three important apertures.
We have one for the
inferior vena cava that sort
of caval opening that occurs at
the level of T8. We then have the aorta
that passes through the diaphragm
then we got the thoracic aorta passing through
the diaphragm passing through this inferior
view we can see at here aorta passing
through, this occurs at T12
level, at the 12th thoracic vertebra.
Here is our caval opening
occuring at T10, sorry the T8
thoracic vertebral level. And then we can see
we have got all oesophageal hiatus
which enables the oesophagus to pass
through and that occurs at T10,
the level of 10th thoracic vertebra.
So we have inferior vena cava at T8,
oesophagus T10, aorta.
So the inferior vena cava T8
the oesophagus at T10 and the aorta
at T12. So let’s move on