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My name is George Dias.
I am a professor of anatomy in
the Department of Anatomy
at the University of Otago.
I'm going to talk to you about
regions of the head region.
The temporal fossa and the
temporomandibular joint.
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Let's start with
the temporal fossa.
The first diagram
shows the skull with
the different cranial bones
that have been given
different colors.
In the second diagram, we have
included the
temporalis muscle onto
the skull as well
as the deep part of
the parotid gland is also
there just behind the
ramus of the mandible.
Also, you can see the
temporal fascia that covers
the temporalis muscle
has been removed but
the edges of the fascia
can be seen on the
second diagram.
The fossa is a space;
therefore, the temporal
fossa is a space.
First, we will look at the
boundaries of this space.
Superiorly, the temporal
fossa is bounded by
the superior temporal line
as is indicated in
the first diagram.
The superior temporal line
is a bony ridge that is
caused by the attachment
of the temporal fascia.
In fact, below the superior
temporal line
there's another line
the inferior temporal line.
The inferior temporal
line demarcates
the peripheral margin of
the attachment of the
temporalis muscle.
We go back to the boundaries.
The superior boundary is
the superior temporal line.
You can see on the
lateral surface
of the skull, the cranium.
The inferior boundary is
the zygomatic arch as
we are demonstrating
in the first image.
Now, we know the zygomatic
arch is formed by two bones.
We have the zygomatic process
of the temporal bone and
the temporal process of
the zygomatic bone
from this arch.
That's the inferior boundary
of the temporal fossa.
The lateral wall of
the temporal fossa is
the fascia that covers
the temporalis muscle,
the dense fibrous tissue sheet.
The temporal fascia is attached,
as we said, to the superior
temporal line superiorly.
Inferiorly, it's attached
to the zygomatic arch that
forms the lateral wall
of the temporal fossa.
The medial wall of
the temporal fossa is
part of the lateral aspect
of the cranial vault.
There are a number
of cranial bones
contributing to the medial
wall of the temporal fossa,
that part of the lateral surface
of the vault of the skull.
Now, what are these bones?
As shown in the first diagram,
part of the purple bone
is the parietal bone.
Then the green bone,
the squamous part of
the temporal bone.
The flat part of
the temporal bone.
For the anteriorly,
you have the frontal bone
contributing to the
temporal fossa.
For the down, there is
another bone, the
blue-colored bone,
which is the greater
wing of the sphenoid.
The sphenoid bone contributes to
the wall of the cranial vault,
that is the greater
wing of the sphenoid,
also therefore, contributes to
the medial wall of
the temporal fossa.
When you discuss the medial
wall of the temporal fossa,
you also must note the
region of the pterion.
The pterion is a region
where four cranial
bones come together.
The four cranial bones
are the parietal bone,
the frontal bone,
the temporal squamous part
of the temporal bone,
and the greater wing
of the sphenoid.
Those four bones are
placed in this area
called the pterion.
In this area, the
skull is relatively
thin and also it has
clinical implications.
There is an important artery.
The branch of the
middle meningeal artery
runs deep into the pterion.
We'll not go into
the details about
the clinical implications
at this point.
The anterior wall of
the temporal fossa is
formed by the frontal bone.
The part that forms
the anterior wall is
the zygomatic process
of the frontal bone.
Then, we have the zygomatic bone
forming the anterior wall.
On the medial aspect,
you find the maxilla.
Those are the bones that form
the anterior wall of
the temporal fossa.
Now that we talked
about boundaries and
the different walls of
the temporal fossa,
what do you find
within this space?
The structure that is found in
the temporal fossa is
the temporalis muscle.
Large, fan-shaped muscle,
which is an important muscle,
is one of the muscles
of mastication.
It's a powerful elevator
of the mandible
so it can retract the mandible.
We'll talk about the mandibular
movements in a little while.
The temporalis muscle is
found in the temporal fossa.
