00:01
Hello, welcome to this topic,
which is going to look at the
anterior lateral abdominal wall,
and specifically the various
muscle layers that form this wall
and how they are arranged.
00:12
So this is a really
complex aspect of anatomy.
00:15
And there's lots of
muscles that reside
in the anterior
lateral abdominal wall.
00:19
So let's have a look at
really what I'm talking about.
00:22
So in this region, we're imagining
the person is laying on their back
and you're looking at
them through their feet.
00:29
So they're laying on bed,
they're laying on their back
and you're standing at
the foot end of the bed,
so you're looking up through them.
00:36
And you can see the
posterior aspect of the body
is at the bottom of the screen,
and the anterior aspect of the body
is at the top of the screen.
00:44
It's important that you're
familiar with that orientation.
00:48
So here we are
looking at the surface
anterolateral abdominal wall.
00:51
Skin, and then situated
deep to that skin,
we have a superficial
layer of fascia
which may contain various
amounts of subcutaneous fat.
01:00
We then have a muscle layer,
and you can see there
there's four paired muscles.
01:05
So the same name for these muscles
on both
the left and right hand side.
01:09
And there's another muscle there
that we can't quite see called
pyramidalis
and we'll come to that
in a moment or two.
01:14
So we have the skin,
the superficial fascia
which contains some
subcutaneous fat.
01:19
We have the muscle layer.
01:21
Then we have another layer of fascia
which we call transversalis fascia.
01:25
We'll come to that
in more detail later on.
01:27
And then deep to that, before we get
into the abdominal cavity proper,
we have the peritoneum, which goes
on to form the peritoneal cavity.
01:35
And again, we'll talk about that
later on as well.
01:38
The peritoneum is
particularly complex.
01:40
So if we then just have a look
at these individual muscle layers.
01:44
We can see we have a series of
what are known as lateral
or anterior lateral muscles
that really start to laterally
and make their way
towards the midline
and they typically come to the
midline as layers of tendon.
01:58
Here, we can see most superficially,
we have external oblique.
02:02
Deep to that
we have internal oblique,
and then we have
transverse abdominis.
02:06
So we have three layers of these
flat muscles that start laterally,
and then curve anteriorly
towards the most midline aspect
towards the midline of the body,
where they actually converge
in the midline.
02:21
The muscles themselves
don't reach the midline,
but they give rise to a tendon,
which we call an aponeurosis.
02:26
Again, we'll come to that
in a moment or two.
02:29
Then running down vertically
through the abdomen,
on the anterior aspect, we have
these anterior vertical muscles,
and these are called
rectus abdominis.
02:39
So a general outline there
of the musculature
on the anterior aspect
of the abdominal wall.