from this goes for the middle mediastinum.
Finally, the lung surface markings you don’t
have to remember, but you need to know that
there are three lobes on the right, upper lobe
and middle lobe, and two lobes on the left.
So, one fissure on the left and two fissures
on the right. What are the two fissures on
Oblique and horizontal.
Oblique, and here? Just the oblique fissure.
On the right, you have the horizontal fissure
and oblique fissure. Surface marking you don’t
have to know because normally when we do surface
marking, we say that the lung is two intercostal
spaces above the pleura. So, it lies so close to
the lung, all the way up to the sixth intercostal
space, here. From the sixth intercostal space
onwards, it is two vertebral spaces away
from the pleura. That’s all you need to remember but
I don’t think you are going to get that
in the exam. So is it the horizontal fissure
you can see on the chest X-ray?
Honestly, I’m confused about what that line --
The horizontal fissure, yeah.
In the exam, they’re not going to ask us
about little intricate bronchopulmonary
segments, are they?
I would say that is one of those 10% things you can’t
really -- they can ask. The syllabus is so vast.
They can ask about that. They
can ask about the liver lobes as well.
So in theory, they can ask about the ten bronchopulmonary
segments on the right and the ten on the
left, but not commonly asked, no. Let
me see. What else were you asking?
I’m asking about horizontal fissure.
Horizontal fissure, okay. So, the lung here,
that’s the pleura going this way.
The lung is all the way, adhere into the
pleura all the way up to the sixth intercostal
space. But when it comes here, it goes a bit
this way. That is your two vertebral spaces.
Now, the easiest way to remember your
the fissures, in the exam. This
is essentially T3 vertebral level.
That’s the middle border of the scapula. If you draw
a line from that vertebral level to the middle
border of the scapula, coming all the way
up to the sixth intercostal space, that is
your oblique fissure. The same thing happens
on the left as well. That is your oblique
fissure. So, what do you see here? That’s
The horizontal fissure is from the fourth
intercostal somewhere there, which cuts across
the midaxillary line. So this is what
you’re seeing in the X-ray. So that is your
upper lobe, middle lobe, and lower lobe. This
is your midaxillary line. So that long
thoracic nerve lies in the midaxillary
line here, and the safe triangle for chest
drain insertion is bounded by the pectoralis
major muscle anteriorly, the long thoracic
nerve posteriorly, and the sixth rib inferiorly.
So this is part of the safe triangle. This is
where you go for chest drain.