hi let's talk about the tongue the
tongue rests in the oral cavity and
there are two distinct parts to it
there's the body of the tongue also
known as the pre-salt whole part and the
root of the tongue aka the post
Sokol part and the the sulcus in
question is called the terminal sulcus
and the terminal sulcus and a cadaveric
tongue can be seen coming back this way
I thought including an illustration down
here to show that completes tongue might
be helpful so here is that terminal
sulcus and where the terminal sulcus
meets in the midline here is the foramen
cecum so the body of the tongue would be
this structure and the root of the
tongue the that structure so the body of
the tongue rests in the oral cavity
where is the root of the tongue is in
the oral pharynx and we can see the
Pilato Galasso fold there which would be
the boundary between the oral cavity and
the oral pharynx so there is also a
median sulcus but because this donor has
been sadly sectioned we don't get to see
that median sulcus there but we can
demonstrate it here in the illustration
would be that ever so slight indentation
that sagittal II divides the right and
the left body of the tongue and we have
a number of papillae on the body of the
tongue many of which are just sensory so
these I'll just circle a group of them
there see those projections so those are
important for for touch those are the
filiform papillae
there are no gustatory receptors
associated with filiform papillae and
then there are funds affirm papillae
fungiform fun G look like little
toadstools and I can circle one there
and there and there
fungiform papillae are associated with
gustatory receptors they they surround
them and they go deep throughout the the
pits of the the fungiform papillae
they're also valid papillae sometimes
called a circumvallate papillae on the
on the illustration here we can see that
these Valley papillae are the final row
of papillae before the terminal sulcus
you can see here on the kena Varick
photograph that these valley papillae
are a little less conceptually
symmetrical than then one would be led
to believe through illustrations alright
so we've got a body and a root of the
tongue the the body of the tongue is
innervated by the lingual nerve so that
would be the the general a ferrant for
the body and if you recall fibers from
the chorda tympani
and that's facial nerve hitchhike along
the lingual nerve for the special
sensory so taste from the the anterior
tongue and that's for most of the the
body of the tongue with the exception of
these valley papillae so this area here
is actually more innervated by the
glossopharyngeal nerve so cranial nerve
number 9 also pharyngeal is
the efferent and then the the special
sensory for the root of the tongue there
are some scattered areas that are
special sensory of the root of the
tongue and the oral pharynx that are
innervated by 10 the the vagus nerve so
in terms of muscles of the tongue we're
talking about largely hypoglossal nerve
so here are some of the the super hyoid
muscles so in the the anterior view here
we can see the anterior bellies of the
digastric muscles they're in the
sagittal sections this would be the
anterior belly of the digastric as'
muscle and then the between them you can
see going this way in there and coming
down from there that's the mylohyoid
muscles the mylohyoid muscle forms the
floor of the oral cavity going along the
midline and there's the hyoid bone there
and we also have the the genial hyoid we
can't see the Jeannie Ohio on the
anterior view but we have a good view of
it the sagittal view so recall there are
two sets of spines there are superior
spines and inferior spines those
inferior spines are the attachment site
for the genial hyoid whereas the
superior spines are um I'm so sorry
let's erase this and start over there
are two sets of spines that are superior
spines and inferior spines the inferior
spines are the attachment sites for the
genial hyoid muscle so here's the genome
hyoid muscle there and the superior
spines are for the genial Colossus
muscle fan-shaped extrinsic muscle of
the tone so extrinsic tongue muscles are
muscles that attach some part of the the
axial skeleton to the tongue and so
there are four major ones Pilate glasses
hi Oh glasses styler glasses and genial
glasses the three that you're
responsible for knowing are hi Oh stylo
and genial glasses so here is the hi Oh
glasses coming from the greater cornu of
the hyoid bone right there
and this hi Oh glasses is going to
divide part of that sublingual space
such that we have the lingual and the
hypoglossal nerves lateral to it and
then we have the lingual artery deep to
that muscle these three extrinsic tongue
muscles are all innervated by the
hypoglossal nerve that would be that
darling there so the the next muscle is
the stylo bosses and the styloid process
of the temporal bone coming down and
laterally and anteriorly inserting
itself into the tongue and then genial
glosses Genea from the genu of the the
mandible this isn't perfectly sadly
section but the genu of the mandible
there so from those superior spines
fanning out words like so so that the
genial Colossus muscle is one of the the
most substantial at extrinsic tongue
muscles the intrinsic tongue muscles are
all innervated by 12 as well so these
are all hyper colossal
the intrinsic tongue muscles play a role
in the the fine-scale movements of the
tongue so we have two sets of
longitudinal muscles so their fibres are
running this way so this is the superior
set here we also have an inferior set
there and then between them we have a
vertical set the transverse muscles
they're a little more difficult to
discern I would say impossible discern
on a sagittal view because they're
running transversely so they're fibers
are going in and out of the of the frame
here and thus it would be impossible to
to see these muscles so we we discussed
elements of the tongue where it is it's
extrinsic and intrinsic muscles I thank
you for your time