hello I am Dr. Aizaz from medicovisual.com. So in the previous lecture we had discussed that
how the this laryngotracheal diverticulum arise and from this laryngotracheal diverticulum
two primary bronchial buds, they arise, so right primary bronchial bud and left primary bronchial
bud. so these primary bronchial buds then form the right primary bronchus so this will form
the right primary bronchus and this will form the left primary bronchus so this will go into
the right lung and this will go into the left lung then from this primary bronchus at the right side
three secondary bronchi arris and two uh secondary bronchi they arise on the left side
so three secondary bronchi on the right and two secondary bronchi on the left side and by the way
these secondary bronchi they are also called lobar bronchi why so because each of these lobar bronchi
they are going to supply a single lobe of lung so naturally it means that because here there are
three lobar bronchi it means that there are three lobes of this right lung so one two and three so
three lobes of this right lung and two lobes for this left lung we do not know the precise reason
for this one hypothesis of this is that on the left side of your mediastinum there is your heart
so the left lung has a less lobes as compared to the right lung so this might be a reason for
less number of lobes of the left lung so let's see how these lobes are uh present here
so here you can see that right lung it has three lobe below this is the upper lobe this is the
middle lobe and this is the inferior or lower lobe so each of the lobe is supplied by its
lobar bronchi or secondary bronchus so upper secondary bronchus middle secondary bronchus and
lower secondary bronchus right so similar to that on the left lung also we have two secondary
bronchi upper and lower and there is no middle bronchus because we have only two lobes then what
happens next is that these are secondary bronchi they further subdivide they further subdivide into
tertiary bronchi so first we have primary then we have secondary bronchi and then another generation
of subdivision leads to formation of tertiary bronchi so here we have several different
tertiary bronchi and these tertiary bronchi they are also called segmental bronchi
why they are called segmental bronchi because they supply each bronchopulmonary segment
of your lung so we have about 10 bronchopulmonary segment of right lung and 10 on the left lung
so here are these bronchopulmonary segments so you can see that upper lobe this is the upper lobe and
upper lobe is further subdivided into three segments similarly middle lobe is
subdivided into two segments and uh the the lower lobe it is also divided into i think four or five
bronchopulmonary segments so what are uh and similar is the case here there is no middle lobe
but superior and inferior lobe it has been divided into two uh subdivisions now the
question is that what are bronchopulmonary segments. bronchopulmonary segments are
isolated structural and functional units of the lung what it means is that if we remove
the let's say this bronchopulmonary segment the other bronchopulmonary segment of the lung they
will continue to function independently right they will continue to perform their function normally
independent of this of the other bronchopulmonary segments so each of the bronchopulmonary segments
they are independent workers they do not rely on the other segments so what are know you know
anatomists they are quite fussy about the names of these bronchopulmonary segments
and they want to know they want you to remember the names of these bronchopulmonary segments
in a proper sequence so let's say this is the first bronchopulmonary segment and it
is called apical bronchopulmonary segment so these anatomists they quite often ask you these segments
in exam and it is quite difficult to memorize that but you know Dr. Aizaz is here to help you
so let's memorize these bronchopulmonary segments by using a funny mnemonic and what is the mnemonic
the mnemonic is that a perverted advocate loves meddling with small [ __ ] oh i know
that mnemonic might be offensive for some of you people but that will help you remember this so
let's remember with this mnemonic so this is the first bronchopulmonary segment of the right lung
and that is called apical bronchopulmonary segment and you can remember it from the "A"
of the mnemonic so "A" perverted advocate so from that "A" you can remember that the first
bronchopulmonary segment of right lung is "A"pical and then this is the second one this one is the
second one and second word of the mnemonic is uh perverted so this is the posterior so Apical
and posterior of course these are named according to their position so here you can see that it is
placed posteriorly so that is posterior and it it is formed it is forming the Apex of right lung so
that is Apical bronchopulmonary segment then uh are perverted so Apical posterior and the third
one is a perverted advocate so advocate a for Anterior so this is Anterior one and this is the
third bronchopulmonary segment of right lung so then what's next in the mnemonic a perverted
advocate loves meddling so from l of loves there is this lateral lobe that is fourth uh not low
sorry fourth segment so fourth bronchopulmonary segment is called lateral bronchopulmonary segment
and that is actually the part of middle lobe of right lung so loves then meddling m for meddling
and m for medial lobe that is the fifth lobe so medial... not lobe again and again i am saying
lobe please don't get confused sorry for that this is fifth bronchopulmonary segment so fifth
bronchopulmonary segment is medial segment so apical apical bronchopulmonary segment posterior
segment anterior segment lateral segment and medial segment first three are the part of
uh upper lobe then fourth and fifth they are the part of middle lobe and from six onwards they are
the part of uh the inferior lobe or lower lobe so let's move forward so small [ __ ] so s s of small
stands for superior bronchopulmonary segment that is the sixth segment of right lungs so superior
bronchopulmonary segment so after superior then there is smal so m stands for medial segment so
here is the medial segment and that is the seventh segment so that is seven segment that is medial
segment then smal so this one is the interior one and this is the eighth so Anterior segment sm a
and then there is ninth one that is lateral segment so this is the lateral segment of
right lung and then finally there is the tenth segment which is the most posterior and that
is posterior basal so actually uh from all these segments from here up to here from 7th up to 10th
these are the basal segments so this is medial basal segment this is anterior basal segment
lateral basal segment and posterior basal segments now the names of the segments of left lung they
are quite similar except we do not have the middle lobe so what how can you remember their name so we
can slightly change the mnemonic for for this what we can say is that a perverted advocate
now it does he does not love meddling so what we can say is that a perverted advocate sucks
intensely small [ __ ] so uh for a perverted advocate again there is apical lobe first is
the apical lobe then second is posterior lobe then uh anterior lobe again now this is your revision
and then we do not have that loves meddling now we have sucks intensely so fourth is the sucks i mean
superior and fifth is the inferior so superior segment and inferior segment and then again rest
are the same what what is this then there is uh yeah sixth superior superior segment of
uh lower lobe this was the superior segment of upper lobe and by the way these two they
are also called linguala so this fourth one is the superior segment of linguala and the sixth
here here is the sixth one so sixth one is the superior segment of lower lobe of left lung then
rest are again the same so seventh one here is the medial segment eight one is uh yeah this is
the medial eighth one is the anterior then uh nine is the lateral and tenth is the posterior basal
segment so medial basal right interior basal lateral basal and posterior basal segment of
left lung so these were the bronchopulmonary segments of right as well as left lungs and
now you know precisely that how do they develop that first there is formation of primary bronchi
then there is formation of skendry or lobar bronchi and then there is formation
of tertiary or segmental bronchi and each of the segmental bronchi it supplies a particular
bronchopulmonary segment of the lung and each bronchopulmonary segment is an independent
structural as well as functional unit of your lung so thank you so much for watching this