Muscles of Respiration: Diaphragm, External Intercostals, Internal Intercostals, Scalenes, Sternocleidomastoid, Pectoralis Minor, Serratus Posterior Superior, …
– Hello, massage nurse.
Today I am gonna be doing lesson 12,
which are the muscles of respiration.
And I've got He-man right
here helping me out today.
So, I'm just getting very creative.
I get to use him for more than
just anatomy and physiology.
So he's gonna help me out.
And I wanna talk about the
main muscle of respiration
and all the other ones that assist.
The main muscle of
respiration is the diaphragm.
And then you've got your internal
and external intercostals,
just kinda like we have the internal
and external abdominals.
And then serratus posterior superior,
and then serratus posterior inferior.
And you should be able
to tell by the names
where they're located.
And, oh, the SCM, the sternocleidomastoid,
and we did that part
of lesson 10 I believe.
And then the scalenes,
anterior, medial, and
posterior, and the pec minor.
I think the pec minor
was part of lesson four.
So lemme touch briefly on each
but let me start with the main
one, which is the diaphragm.
The diaphragm separates
the thoracic cavity
from the abdominopelvic cavity.
And it's a dome shaped muscle.
So it's like right underneath
here, is like a dome,
you know, right here.
And it originates from T12,
so that's posteriorly
but inside, you know,
T12 through L1 and 2,
and it inserts into in the central tendon.
The central tendon looks like
a four-leaf clover tendon,
and it's right in the
middle of the diaphragm.
Remember, the aponeurosis
is a flat sheet tendon.
So, that's where it inserts.
So the diaphragm is the
main muscle for inspiration.
And here are your lungs.
You know, a lot of people
don't realize that your lungs
go all the way up, you know,
to almost the first rib.
They're about the size of your open hand.
So, when you inhale
you know, when you inhale,
take a deep breath right now and inhale,
and you can see that your, you know
your rib cage expands, okay?
So when you inhale, you're
pulling down the air,
the diaphragm is being pulled
down by the central tendon.
So it increases the
surface area in the lungs,
and the atmospheric pressure
goes through your nostrils
because the atmospheric pressure is higher
than what's in your lungs
when you breathe in.
So it forces the air in.
One of the main muscles
of that is the external,
the external intercostals.
Remember inter costal.
Inter means in between.
So intercostals is in between.
And let me show you right here
the external intercostals
are more superficial,
and they are, they start
like not at the sternum.
This is the cartilage right here.
So they start where the ribs starts.
So the rib starts right here
and they go from the
superior part of the rib
to the top of the, oh, I'm sorry.
They start from the
superior border of the rib
to the inferior border of the next rib.
Intercostal means right
and between each rib.
So, the external and internal intercostals
go from rib to rib, from rib to rib.
And the external intercostals are also,
lemme show you right
here, really close up.
Right here you can see
it's kinda like in between here,
this is ribs
seven, eight nine,
and in between here, I
don't know if you can see
that little lattice work right there.
You know, where they cross.
This are very much like the
internal and external obliques.
Remember that the external obliques
is like putting your
hands in your pockets.
Well, guess what?
The external intercostals
are the same way,
they go this way.
And then the internal
intercostals go the opposite way.
So, that forms like a little mesh,
like a little, you know, like,
yeah, like a little safety
you know, like once the fibers are going,
you know, this way on the external
and the internals the fibers
are going the opposite way.
And you could really see it right here.
If you can see right
here in between each rib
and the external and internal intercostals
are in between each of the
ribs, and the diaphragm,
you know, is right here,
separating the thoracic cavity
and the abdominopelvic cavity.
So I wanna remove the lungs, you know,
so these are the lungs, and, you know,
you can see the lungs are right here.
And then if you remove,
if I was to remove the
liver and all of that
let's see if I can,
then the diaphragm would be right here.
So, the diaphragm would be
all of this right here, okay?
And like I said, it originates
from the posterior part
from T, you know, T12 to L1 and 2, okay?
And so this separates right here.
Now when you exhale, so you inhale
and the external intercostals
expand your rib cage,
when you, you know,
when you exhale the diaphragm
relaxes and it puts pressure
so it goes up, and it puts
pressure in your lungs.
So now the pressure is
higher in your lungs,
and so, than the atmospheric pressure,
so then that's when you're
able to exhale you know,
because it switches.
When the atmospheric pressure
is higher on the outside
then that's when you inhale.
So it forces the, you know,
the oxygen into your lungs.
And when you exhale the diaphragm relaxes
and the internal intercostals,
you know, help to,
you know, relax the diaphragm in the ribs
so that the pressure is higher here,
and it can push the oxygen
or the carbon dioxide
out of your nostrils.
Also the scalenes, you know,
the scalenes also help,
because the scalenes remember,
they originate from C3,
4, 5, 6, the anterior,
and it inserts on your top
rib right below the scapula.
The medias originates from C2 to C7,
and inserts also in the first rib.
And then the posterior
originates from C5, 6, 7,
and that one inserts on the second ribs.
So guess what they do.
They also help elevate
you know, the first and the second ribs
along with the SCM,
the sternocleidomastoid
that originates you know, at
the sternum, the clavicle,
inserts at the mastoid process.
So, and the pec minor.
Don't forget about the pec minor.
The pec minor originates
in ribs three, four, five,
and then inserts at the
coracoid process of the scapula
right here on the anterior part.
So you've got a lot of help,
you know, to help you
lift up that rib cage,
you know, to expand that rib cage,
so you can inhale and take a deep breath.
So those are the muscles from the anterior
and the intercostals do
go all the way around,
you know, they start right
here where the ribs begin
but they do go all the way
back, you know, to the posterior
you know, to all the
way around the rib cage.
So let's talk about the posterior muscles,
because I know you guys heard,
you know, the serratus posterior
you know, superior and inferior,
and these are in the back.
They are,
the serratus posterior superior
is beneath the rhomboids.
You know, the rhomboids are, you know
below, you know, on top of the serratus.
And lemme tell you, the
serratus posterior superior
originates from C7 to T3,
almost right where the
rhomboids originate also.
So this one is up here
and then if you have a
serratus posterior superior
then you're gonna have a
serratus posterior inferior.
And that one originates from
T11 and the first two lumbars
lumbars, L1 and L2.
Okay, and they insert in the ribs.
So you also have assistance, you know
from the posterior part,
you know, to kinda help
open up that rib cage
when you inhale and you exhale.
So, let's review them again.
The main muscle of
respiration is the diaphragm
which separates the abdominopelvic cavity,
and the thoracic cavity.
It's a dome shaped muscle.
And then in the posterior part,
you have the serratus posterior superior,
serratus posterior inferior.
And these are underneath
the trapezius, the lats.
You know, I've been posting on Instagram
you know, some of the videos that,
remember guys that these
muscles come in layers,
you know like the erector spinaes
and the paraspinal muscles
and, you know, those are
underneath the trapezius
and underneath the lats, you know,
so these muscles are also underneath
you know, they're very close to the ribs
'cause they, you know, they
help open up the rib cage.
On the anterior part, lemme
see if we can rotate him
without dropping him will
be the sternocleidomastoid
the scalenes, the pec
minor, and the intercostals,
you know the exterior
and internal intercostals
are very similar to the
external and internal obliques.
Oh, and there's also inner intercostals.
So there's three, also like the abdominal,
you know, muscles where
you have the internal
and external obliques
and the rectus abdominis.
We also have three,
you know, intercostals.
The external intercostals,
internal intercostals
and inner intercostals.
So, you know, very similar to help you
you know, take a deep breath.
And I think kids you know,
usually inhale anywhere from,
you know, 16 times, 12,
12 to 16 times for adults
and children may you know,
have respiration a little bit faster.
And, I always like to talk
about, you know, respiration
'cause it's so important,
especially when you meditate
you know, to really expand your belly
really bring in the oxygen,
you know, all the way,
expand your belly, get your
abdominals also involved.
If you notice, watch a baby breathe.
If you watch a newborn breathe,
you can see that they
really engage the abdomen.
And that's very good to, you know
to bring the oxygen all the
way down into your lungs.
And, I think I'll talk a little
bit more about respiration
and the respiratory system.
But anyway, those are the
muscles of respiration.
And this is now, this is the last one
for the kinesiology class.
I'm gonna start, you know,
teaching some of the things,
but I'll keep you posted.
And until the next time,
create a great day.

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