hi everyone let's talk about the laryngeal cartilages the laryngeal cartilages as a
complex are referred to as the laryngoskeleton the Laryngoskeleton consists of all of the
laryngeal cartilages of the larynx to the right here we can see the anterior view of the neck with
the infrahyoid muscles reflected away laterally we can see the contents of the carotid sheath
we can also see anteriorly here the thyroid gland that would be the right lobe of the
gland and the left lobe of the gland and we can see most prominently here along the midline that
would be one lamina of the thyroid cartilage that would be the other lamina of the thyroid
cartilage and they would come together here as the laryngeal prominence aka the Adam's apple
and the thyroid cartilage is suspended from the hyoid bone which is located about here
by the thyrohyoid membrane which I'm drawing in right there the hyoid bone is approximately
at c3 c4 vertebral level the thyroid cartilage is approximately at c4 vertebral level the thyroid
cartilage sits atop the cricoid cartilage which I'm drawing in here which is currently obscured
by the cricothyroid muscles and then between the two we have the cricothyroid membrane and
this portion is the median cricothyroid membrane this is the the portion which is incised when one
performs a cricothyrotomy now looking over here on the left hand side of the screen
we see a right lateral view of the larynx so i'll outline the thyroid cartilage here
the thyroid cartilage is incomplete posteriorly so it is most robust anteriorly and we can
see here is a superior horn and there is the inferior horn and that inferior horn of the
thyroid cartilage articulates with the cricoid cartilage to form the cricothyroid joint so this
is a pivot joint here and what happens when the cricothyroid muscle which has been removed but
which would be located there contracts that pulls the thyroid cartilage anteriorly and
inferiorly and what that does is it puts tension on the vocal ligament or the vocal
cords to increase pitch now when we look at the laryngoskeleton from a posterior view we can we
can see a completely different perspective so just for your own knowledge the the cervical spine has
been cut so there's one side of it and there's the other side of it and it has been reflected
out laterally in a way open almost as if it were a book and we can see the the right greater cornu
or Horn of the hyoid bone there the left is probably about there but it's obscured by
some tissue I can see there's the superior horn of the thyroid cartilage so I'm outlining that
cartilage there I can see a little bit of it over there as well here is the cricoid
cartilage so wrapping around like so and going down and we can see that the cricoid cartilage
is very robust posteriorly the cricoid cartilage is the only laryngeal cartilage which is complete
360 degrees about the larynx so cricoid comes from Cricios which is greek for a ring now sitting
atop the cricoid lamina here in the posterior are the arytenoid cartilages arytenoid cartilage is
our funnel-shaped and they are obscured here by the posterior a retinoid muscles so we have the
oblique which are there and the transverse which are there let me get that out of our way so these
arytenoid cartilages these sit atop the the cricoid cartilage and they are the most kinetic
part of the laryngoskeleton most nearly all of the intrinsic laryngeal muscles are going
to act upon the arytenoid cartilages either you know pivoting them different directions sliding
them together pulling them apart because it's these are rima cartilages which are going to
attach to the vocal ligaments which then attach to the thyroid cartilage so this is how we can
maintain the the patency of the airway or close off the airway or effect tension or or
tambour on the the vocal folds sitting atop the arytenoid cartilages are the curricula
cartilages though you're not responsible for seeing these in the laboratory and then the
Cuneiform cartilages would rest in the folds lateral to that finally probably one of the the
more conspicuous things that we can see here in this photograph is the epiglottis should be the
epiglottis cartilage invested by mucosa and so this epiglottis cartilage is a single midline
unpaired cartilage which can protect the opening to the larynx during times of deglutition or or
swallowing so we can see here all of this rugose area that's the root of the tongue and as you can
imagine the lyrics here is going to sit anterior to the laryngopharynx and so air is exchanged
anteriorly posterior to this the laryngopharynx would be contiguous posteriorly with the esophagus
so this is where the aerodigestive pathway would diverge and it's you know approximately
at the level of c6 or the the base of the cricoid cartilage where foodstuffs or liquids are funneled
down towards the the stomach via the esophagus where is air answers in through the laryngeal
Inlet and heads towards the respiratory system so we've discussed the various cartilages which
comprise the laryngoskeleton and a little bit of what they've done thank you for your time