where the obturator membrane would be located.
The pelvic floor is the inferior aspect of
the pelvis. The pelvic floor is very, very
important in supporting the pelvic viscera.
If pelvic floor components become weak, you
can have a prolapse of pelvic viscera. So,
they would start to protrude inferiorly through
a weak floor.
The various components that form the floor
would be the levator ani muscle, the coccygeus
muscle, sometimes referred to as the ischiococcygeus.
We have the perineal membrane and we have
muscles that occupy the deep perineal pouch.
We do see the levator ani in this view and
we also see the coccygeus muscle in this view,
but the perineal membrane and the deep perineal
pouch will lie just inferior to the muscles
that are forming the pelvic floor. So, we'll
have an opportunity to view them in greater
As we can see in this slide, the pelvic floor
does provide for openings. This will allow
the passage of various components that are
found within pelvic region. Here, we have
an anterior opening, or hiatus. This is the
urogenital hiatus. And so, urogenital structures
can pass through this particular opening in
the floor. And just posterior to it, we have
a narrower opening or hiatus and this is the
anal hiatus. And so, the anal canal will pass
through this smaller opening.
Now, we'll focus our attention on the other
components of the pelvic floor, the perineal
membrane and the deep perineal pouch. There
are gender differences between men and women
of this particular region. We'll explore those
differences a little bit. But, here, we're
looking at the perineal membrane, a deep perineal
pouch in a man.
The first component to point out has been
reflected almost in its entirety, but here,
we have a membranous structure that's being
pulled back just a little bit by the forceps.
This represents the perineal membrane. It
is covering everything that we see in through
here. So, it has been removed to kind of open
up our view to see some of the other contents,
then, that are located deep to it and those
contents that are deep to the perineal membrane
are located in the deep perineal
pouch. So, those contents would be the urethra
and we see the lumen of the urethra here.
So, it's passing through that urogenital hiatus
that we saw in the pelvic floor.
There is muscle surrounding it at this level
and those muscle fibers constitute the external
urethral sphincter. We also see muscle fibers
that are running transversely through the
deep perineal pouch. These muscle fibers constitute
the deep transverse perineal muscles and they
meet in the midline. So, we do have a right
one and a left one.
Embedded within the deep perineal pouch in
a man would be the bulbourethral glands, also
referred to as Cowper's glands and one of
those has been exposed here. And so, the muscle
has been removed, lifting off the roof, so
that we can see the bulbourethral gland here
in the deep perineal pouch. Here are the muscles
still intact. And you can kind of see the
bulge of that bulbourethral gland.
Lastly, you'll have neurovascular structures
that supply the penis. They're coming into
this area right through here. These
neurovascular structures pass through the
deep perineal pouch and then we can see them
emerging at this particular point and then
they will follow the penis.
Here, we're looking at perineal membrane
and deep perineal pouch in a woman. The membrane,
unlike the previous slide, is intact. So,
here is this whitish perineal membrane fully
covering the deep perineal pouch.
Structures that are found in the deep perineal
pouch in a woman would include the urethra
and we see that right in through here. We
can also see the external urethral sphincter.
So, these are certainly shared between men
If we peel back the perineal membrane, we
would see the same deep transverse perineal
muscles meeting in the midline. But, two structures
that are unique in women, which are not depicted
here because the membrane is intact, in place
and is covering them up, but two structures
unique to the deep perineal pouch
in a woman would be the compressor urethrae
muscle and the sphincter urethrovaginalis
There is sexual dimorphism of the pelvis or