hi let's talk about the laryngeal cartilages aka the laryngoskeleton in this video we'll
discuss the major cartilaginous parts of the laryngoskeleton and relate important features of
these cartilages to the structure and functions of the larynx but first what is the larynx the
larynx or colloquially the voice box is the most proximal part of the dedicated respiratory tract
anything more proximal to this is going to be a shared aerodigestive pathway it is inferior
to the hydroid bone it hangs from the hyoid bone by the thyrohyoid membrane and it sits above the
trachea it hangs the trachea by the cricotracheal membrane it is anterior to the laryngopharynx
and it is going to be at approximately the c4 through c6 vertebral level but there is variation
amongst individuals the laryngoskeleton consists of nine major cartilages and some minor cartilages
these include the thyroid cartilage which sits atop the cricoid cartilage
as we spin this around and look posteriorly we can see that connecting to the thyroid
cartilage is the epiglottic cartilage here's the cricoid cartilage in the posterior which
it is more robust so that is the top of the cricoid cartilage
and upon the cricoid cartilage is the arytenoid cartilage on either side and atop the arytenoid
the corniculate cartilages and then there is an airy epiglottic fold there and within
the cuneiform cartilages these are all hyaline cartilage and they actually begin to calcify
at about 18 years of age now let's look at some of the features of the laryngoskeleton let's start
with the thyroid cartilage because it is a massive component to the larynx the thyroid cartilage is
only complete anteriorly and laterally it consists of two laminae which come together along the
midline anteriorly and there is a robust piece of cartilage there known as the laryngeal prominence
this is colloquially referred to as the adam's apple as we move posteriorly we see that there are
two sets of horns there are superior horns these superior horns are going to ally with the greater
cornua or horns of the hyoid and then there are inferior horns
that are going to form a joint called the cricothyroid joint with the cricoid cartilage
that cricoid cartilage is the only element of the laryngoskeleton that is complete 360 degrees about
the airway and posteriorly this cricoid lamina is the base upon which the arytenoid cartilages
sit the epiglottic cartilage has a stem and a leaf and that is going to articulate with
the thyroid cartilage anteriorly let's take a look at those arytenoid cartilages they are
very important structures for the function of the larynx they're the most kinetic elements
of the larynx there is some motion at the cricothyroid joint but not as much as with
these arytenoid cartilages so as we look at them superiorly we see that they have two important
processes anteriorly there are vocal processes and posterior laterally there are muscular processes
the vocal processes attach to a vocal ligament which then attaches to the thyroid cartilage
those vocal ligaments are going to be the basis for the vocal cords so once they are invested
by mucosa of the larynx as well as some of the intrinsic musculature they become the vocal cords
these muscular processes are structures upon which some of the intrinsic laryngeal muscles
may attach so that they can affect the motion of the aretenoid cartilages
these are retinoid cartilages they may pivot so we see them pivoting their vocal process outward
there and as they do the vocal ligaments and hence the folds are going to abduct or they may be
pivoting medially and that vocal ligament in the vocal folds will adduct so this will either expand
the rima glottitus or this space or it will narrow it
also as accessory cartilages atop the arenoid there are corniculate cartilages and then
cuneiform cartilages these help to maintain patency of the laryngeal inlet
so we've discussed the major elements of the laryngoskeleton the individual cartilages which
comprise it some of their more important features as well as how these cartilages move with respect
to one another this is your summary slide and i thank you for your time