Muscles of Facial Expression

Muscles of Facial Expression


– [Voiceover] So now
we’re going to take a look at the muscles of facial expression. As we start looking at
them, we’ll notice that this side of the model is going
to have the deeper muscles while this side of the
model, will have more superficial muscles. It doesn’t mean that the
other side doesn’t have it, it just means that you
can’t see the deep ones when you have the
superficial muscles in place. So this particular model
has both the superficial and the deep. We’ll start off with the buccinator. Now this muscle is found on
the deeper side of the skull. You find right here
running laterally away from the corner of the lips. So this is a little bit deeper muscle. You can see there are
muscles that have been cut away from this point. Now the action of buccinator
is going to be causing compression of the cheek. So to help to compress the cheek. If we rotate this a little bit, we can now see this is
where the mentalis muscle will be, right at the chin. The mental region. The mentalis muscle. Now the mentalis muscle has an
action of wrinkling the chin. The mentalis muscle. And this particular model
has a little bit of skin right here covering part of the muscle. Next up, we have the orbicularis oculi. Now this one’s found a little
more on the superficial side of things. This circular muscle right here is your orbicularis oculi. Orbicularis think of orb or around. It’s a round muscle going around the eye. Oculi. So orbicularis oculi. The action of orbicularis
oculi is to close the eye or close the eyelid. So orbicularis oculi. The orbicularis oris, again,
a circular round muscle is going around the mouth, right where the lips are. Orbicularis oris. Now this orbicularis oris has an action of closing the lips. One thing to keep in mind is
while the orbicularis oris close the lips, it does
not close the mouth. The jaw or the mandible is going to closed with other muscles. The orbicularis oris only close the lips. The risorius muscle. Now the risorius muscle
is going to be seen way over here and this
one’s actually cut a right so we can see that we have
the buccinators deep here and right here is the risorius muscle. Risorius. Now risorius is going to
pull the lateral corner of the lip outwards or laterally. This will pull the lips laterally. The risorius muscle. Next up we’ll look at zygomaticus major and zygomaticus minor. Now these are two muscles. A lot of times referred
to as zygomaticus muscles or zygomacis group. But these zygomaticus major
is going to be more lateral while this zygomaticus
minor is a more medial. Typically the major will
be a little bit larger but depending on model it might not be very evident. So zygomatis major, zygomatis minor. Both of the zygomaticus muscles. So zygomaticus major and zygomaticus minor will draw the corns of the lips upwards. We kind of think of it as smiling. The zygomaticus muscles. Major, minor help you smile. Then we have the frontalis muscle or as known as the
frontal belly sometimes. This muscle right here which
is right in your frontal region is going to be the frontalis muscle or the frontal belly. The reason sometimes referred
to as a frontal belly is because it runs all the
way along the top of the skull all the way back against the petalis. Now the action of the frontalis muscle is going to be elevate your eyebrows. So frontalis muscle will
elevate the eyebrows. Now this is going to be a different model, a different view but what’s
nice about this model is it shows this muscle right here which is platysma. A lot of models will not show platysma because it’s very superficial. Now if you notice, this
model has the platysma muscle running with the fibers in this direction. You can see there’s a muscle deep to it right here, this sternocleidomastoid. So platysma is a very superficial muscle right along this direction of neck. Now as far as action goes, the platysma is going to tense the foccia of the neck to cause the neck to
kind of tense up tenses the foccia of the neck. The platysma muscle.

Leave a Reply

Your email address will not be published. Required fields are marked *