00:01
The next region we'll look at
is the area under the tongue
or what we call the
sublingual region.
00:09
So here we see the intrinsic
muscles of the tongue
sitting on the superior
aspect of the tongue.
00:17
We also see some
of the oral mucosa
or the mucosa that
lines the oral cavity.
00:23
Medially, we see one of those extrinsic
tongue muscles, the genioglossus.
00:29
As well as the geniohyoid,
one of the suprahyoid muscles.
00:35
In the inferior lateral aspect,
we see the wide flat muscle that
we call the mylohyoid muscle.
00:42
And then anteriorly,
we have the mandible.
00:47
Posteriorly,
we have communications
with the submandibular
and parapharyngeal spaces.
00:56
In terms of contents of
the sublingual region,
we see the hyoglossus muscle,
which is very closely related
to one of our salivary glands,
the submandibular gland.
01:12
We see the submandibular gland
has this duct to carry its
contents out to the oral cavity
called the submandibular duct.
01:23
And this submandibular gland
is sort of pinching around
that other muscle we saw that
has a very wide flat shape
called the mylohyoid.
01:33
And then beyond that,
we have our smaller
sublingual gland
which is directly
under the tongue.
01:40
And there are sublingual ducts
that enter directly
into the oral cavity.
01:45
And then some of the other ones
will join the submandibular duct
on its way into the
opening of the oral cavity.
01:52
We also have the lingual nerve,
which is that branch of the
mandibular nerve or cranial nerve V3
coming down to
supply the tongue.
02:05
From sort of a
posterior lateral view,
we can see a different aspect
of the submandibular gland here
and we can see just
how closely it is
associated to that mylohyoid,
sort of wrapping
around the mylohyoid.
02:20
We also see the lingual
nerve coming down
and innervating the tongue,
we see the submandibular duct
making its way towards
the oral cavity
to deliver saliva.
02:31
And then the sublingual gland,
which is again a bit smaller
than the submandibular gland
but located more directly
underneath the tongue.
02:40
Here we see the common
carotid branching
into the external carotid
while the internal carotid makes
its way to the cranial cavity.
02:49
One of those branches
of the external carotid
is the lingual artery,
which we can see here traveling
past the hyoglossus muscle.
02:58
We have the dorsal lingual
branch and sublingual branch,
as well as the deep
lingual branch.
03:07
We also have venous
drainage in this area
that pretty much mirrors
the arterial supply.
03:14
And we see it's coming
back to the lingual vein
on its way to the
common facial vein
and eventually into
the internal jugular.
03:24
Although there's
variation in this area
in terms of whether it's all
passing deep two or lateral two
the hyoglossus muscle.
03:33
In terms of nerves,
here's where we see
the hypoglossal nerve
or cranial nerve XII.
03:40
More superiorly is where
we see the lingual nerve
or cranial nerve V3.
03:47
And it's coming from
a more superior aspect
because it actually parallels
the inferior alveolar nerve
that was coming through the
mandibular foramen or canal.
03:57
It also forms a
little ganglion here
called the
submandibular ganglion.
04:04
Now the submandibular
ganglion is another area
where the cranial nerve
VII is hitching a ride
with the lingual nerve.
04:13
So here we see the
lingual nerve coming down
and those fibers that are being
provided by cranial nerve V3
are providing general
sensation to the tongue.
04:25
But via this little shortcut
called the chorda tympani,
some branches of
cranial nerve VII
will join the lingual nerve.
04:33
On its way to provide
taste sensation
to the anterior two
thirds of the tongue.
04:38
But it's also going to provide
some autonomic innervation,
specifically the preganglionic
fibers of parasympathetic fibers
are going to go towards
the submandibular ganglion.
04:52
And then from there,
there are going to be branches
that are going to supply
the sublingual gland
and the submandibular gland.
05:00
And in this way
cranial nerve VII,
again pretty much hitches a ride to
carry out its functions in this area,
namely taste sensation to the
anterior two thirds of the tongue
and parasympathetic innervation
to the sublingual and
submandibular salivary glands.