00:01
If we move on to the cutaneous
innervation, then this
is very similar to the upper limb, and we
have a whole series of dermatomes, regions
of the skin on the lower limb that have specific
cutaneous innervation. We can see we have
T12, L1, L2, L3, L4, L5, and then we move
on to the sacral spinal cord segments, as
then we pass up the posterior surface of the
limb. So if we look at this in more detail,
the cutaneous nerve supplies the skin of the
lower limb creating these dermatomes, and
each dermatome is innervated by a spinal cord
segment. So we can see L1 through to S5, the
perianal region. We can even see details here,
L4, L5, and S1 supplying the palm of the foot.
00:50
If we look at L1 to L5, you can see these
were series of bands running down the anterior
aspect of the lower limb. So, around the knee
region and the medial leg, we have L4.
01:02
And the medial leg to the great toe, we have L5,
we can see running down here. S1 to S5 forms
more vertical bands that are running up the
posterior aspect of the lower limb, and S1,
we have the lateral foot we can see here,
and we also have the heel. So we can see we
have the dermatomal distribution running over
the anterior and posterior surfaces of the
lower limb. Again, we have the dermatomal
distribution, but we also have specific cutaneous
nerves that are coming from the lumbosacral
plexus which we'll detail. Here, we can
see specific nerves supplying specific regions.
We can pick up the lateral cutaneous nerve
of the thigh that supply the lateral aspect
of the thigh. We can see the genitofemoral
nerves coming here supplying a small region
on the anterior thigh. Cutaneous branches
from the femoral nerve. We've got the saphenous
nerve, a branch of the femoral nerve supplying
the medial aspect of the leg. We can see the
common fibular supplying the lateral aspect
of the leg. And posteriorly, we can see the
posterior cutaneous nerve of the thigh supplying
the posterior aspect of the thigh. We can see
obturator nerve supplying the medial aspect.
02:26
And we can see clunial nerves supplying the
skin over the gluteal region. Again, we have
those named branches: iliohypogastric, ilioinguinal,
we can see these supplying parts of the abdominal
wall and the lower abdomen passing over the
inguinal region, lateral cutaneous nerve of
the thigh, and the genitofemoral and the obturator
I've already mentioned. We can go on to
detail the femoral, saphenous, common fibular,
deep fibular and superficial fibular nerves.
02:58
And we can see how these are supplying various
regions of the lower limb. So in this lecture,
we've looked at the fascia of the lower limb,
both the superficial and deep, specifically
looking at the fascia lata. We looked at the
venous drainage, the dorsal venous network
giving rise to the great saphenous vein and
the short saphenous vein with these draining
into the femoral vein and the popliteal vein,
respectively. We then looked at the cutaneous
innervations with the dermatomal distribution.
Again, this is determined by the developmental
process similar to the upper limb. So I didn't
mention it in any detail today but it's
the same process. And the cutaneous nerves
from the spinal cord segments, L1 through
S5 that supplies the skin of the lower limb.