hello anatomy friends we have reached our final station for the musculoskeletal lab one so station
28 and we are going to look at some of the pelvic musculature as i mentioned in the lecture videos
some of the perineal musculature is going to be discussed in more detail in the reproductive
portion of the course we're more focused on the pelvic diaphragm region so these more superficial
muscles here are going to be discussed later where we're more focused is more in this pelvic
diaphragm region the pelvic diaphragm of course will extend anteriorly but it would be deep to
this perineal membrane right here so kind of from here this way you'll talk about later
so don't worry that will that will come up in subsequent portions of the course so the coccygeus
muscle is going to be the more posterior kind of inferior one it is going to be located right about
here ish the coccyx would be located here because we're looking at a straight kind of inferior
view but um in a lithotomy type of position with the the legs or the lower limbs kind of spread in
order to get a better view of this region now the levator ai as we discussed is going to be
the majority of the pelvic diaphragm but this does make the coccygeus muscle look a little bit bigger
than i would typically have it but that is because we can't see some of the levator anae
because it would be deep to the to this portion of the perineal membrane region but recall the
levator ani is going to be near the external anal sphincter which is right in this region
and then it will have certain muscle fibers that are going to surround the vaginal orifice
or the orifice associated with the urethra as well so it will be a larger than it will
then you can actually see on this particular image but i do like this image because this
is kind of giving you an idea of this musculature from a lithotomy position
now one other muscle that we had mentioned in terms of the pelvis and it also is going to be
play a role in terms of the lower limb is the piriformis and the piriformis is going to have
its more proximal attachment on the sacrum and it is going to be that only is that muscle that is
going to traverse the greater sciatic notch and foramen in order to exit the pelvis because it
like many other muscles are going is going to insert on the greater trochanter of the femur and
so here you can see this is the gluteus maximus that's been reflected this is the gluteus medius
the minimus is going to be deep to this and then here is this piriformis that
kind of jumps right out of that greater sciatic notch in order to get to the greater trochanter
and one of the reasons that i wanted to use this particular view which is a in or excuse
me a posterior view of the gluteal region is because the reason that piriformis is discussed
often is not only because it's going to have an attachment to the greater trochanter but because
you have a lot of neurovasculature that is going to exit through that greater sciatic notch as well
and a particular importance is going to be the sciatic nerve which you can see on that
sciatic nerve kind of being this large structure moving inferiorly from that greater sciatic notch
and inferior to the piriformis so if you think about this particular muscle hypertrophying
if it gets too large it could feasibly pinch on the sciatic nerve or cause compression there
okay excellent so you have made it through 28 stations of mostly the axial portion of the
body with some other a few other things added in and in our next lab visit we will have a
more focus on the appendicular skeleton and the muscles and joints associated with that
so as you move through here if you're having any confusion regarding identification of
some of these structures please feel free to reach out to me with any of those questions
and i thank you for your time and attention