also the ischiopubic ramus which runs away
towards the ischial bone. Here, if we look
at the lateral view. So, again, we have got
a hemisected pelvis here and then we are looking
inferiorly from the bottom looking up into
the pelvis on this diagram on the right hand
side. Again, we can recognise various structures,
we can recognise the pubic symphysis here.
We can recognise the pubic symphysis. This
time it’s inferior aspect here. We can recognise
the superior pubic ramus and the inferior
pubic ramus here. We, again, can recognise
the pelvic brim. We can look posteriorly and
see the sacral promontory which we can indicate
here and again, we can see the ischial tuberosities
here and the ischial spines here. We can also
see those on this inferior view where we have
the ischial tuberosities here and the ischial
spines here. And if you remember, these are
important because this is the landmarks that
attach the sacrotuberous and the sacrospinous
ligaments to the sacrum.
So, let's remind ourselves of the greater
sciatic notch which we can see here and the
lesser sciatic notch which we can see here.
These greater and lesser sciatic notches are
converted into foramina via these two ligaments.
We can see from the ischial spine running
towards the sacrum, we have the sacrospinous
ligament. And we can see running from the
ischial tuberosity also up towards the sacrum,
we can see we have the sacrotuberous ligament.
These two ligaments are really important.
As we spoke about, during the lecture on the
branches of the internal iliac, that converting
these greater and lesser sciatic notches into
greater and lesser sciatic foramina. And these
are important apertures, important holes,
as they allow structures to pass in and out
of the pelvis. They allow the superior, inferior
gluteal blood vessels to pass from the pelvis
to the gluteal region. We will see that it
allies the piriformis, an important muscle
to pass out of the pelvis. And it gives the
potential for blood vessels to pass into the
perineum passing underneath the pelvic floor
and into the peritoneum like the internal
pudendal artery did. Again, we can see these
ligaments passing through to the sacrum here
where we have the ischial tuberosity, we can
see the sacrotuberous ligament and we can
see ischial spine. We have the sacrospinous
ligament. Once again, I just want to draw
your attention to the obturator foramen, which
we can see here. This foramina allow the obturator
nerve, artery and the vein to leave the pelvis
and pass to the medial aspect of the thigh.