Download psoas major muscle

1
Sensory and motor innervation of the whole
.lower limb
arises from the spinal roots L1-S4
Lumbal plexus
Sacral plexus
2
Anterior rami of
.upper 4 lumbar
spinal nerves (+L5)
and from the
contribution of
subcostal nerve
(T12)
in the lumbar
region, within
the psoas major
muscle.
3
.L1
gives rise to the iliohypogastric and ilioinguinal nerves
L1 + L2 gives rise to the genitofemoral nerve
L2 + L3 gives rise to the lateral femoral cutaneous
L2 + L3 + L4 give rise to the femoral and obturator nerves
L4 + L5 give rise to the lumbosacral trunk which joins sacral
nerves to form the sacral plexus.
4
(L2-L4)
largest
branch
.
both motor and sensory.
Emerges from the lateral
border of the psoas major
Flexors of the hip and
extensors of the knee
Skin of the anterior and
lateral thigh, medial leg
and foot
5
largest cutaneous
branch
of the femoral
.
nerve
continuation of the
femoral nerve
Skin of medial aspects
of leg and foot
6
Emerges from the medial
border
of the psoas
.
major
Leaves the lesser
pelvis through
the obturator canal
Skin on the superior
medial thigh
Adductor muscles of the
leg
7
Descending part of
the
L4 nerve unites
.
with the anterior
ramus of the L5
nerve to form the
lumbosacral trunk.
Participates in the
formation of the
sacral plexus with
the anterior rami
of S1-S4 nerves.
8
Enter the abdomen and
run
obliquely across
.
the quadratus
lumborum muscle
behind the kidney.
Abdominal muscles
Skin of the inguinal
and pubic regions.
9
uinal & iliohypogastric nerves
Pierces the psoas major
and emerges on its
anterior surface.
Skin of the middle
anterior thigh; male
scrotum and cremaster
muscle; female labia
majora.
10
Runs
.
inferolaterally on
the iliacus and
enters the thigh
deep to the
inguinal
ligament/iliopubic
tract
Skin on the
anterolateral
surface of the
thigh
11
The lumbar
plexus is also
connected with
the lumbar part
of the
sympathetic
nervous system
via two or
three long
communicating
branches.
12
anterior rami of S1
to
S4, and the
.
lumbosacral trunk
(L4 and L5).
formed in relation to
the anterior surface
of the piriformis
muscle
located on the
posterolateral wall
of the lesser pelvis.
13
o Largest nerve in
the body.
.
o The most lateral
structure
emerging through
the greater
sciatic foramen
inferior to the
piriformis and
enters the
gluteal region
o Posterior aspect
of the thigh and
the entire leg
and foot
14
o Leaves the
. gluteal region by
passing deep to
the long head of
the biceps
femoris,at the
lower margin of
the quadratus
femoris muscle
o Divides into the
common peroneal
and tibial
nerves, at a
variable site
above the
popliteal fossa
15
o Main nerve of the
perineum
and the chief
.
sensory nerve of the
external genitalia
o Enters the gluteal
region through the greater
sciatic foramen inferior to
the piriformis muscle & medial
to the sciatic nerve.
o Passes through the
lesser sciatic foramen to
enter the perineum.
ono branches in the
gluteal region.
16
Superior gluteal nerve
leaves
the pelvic
.
cavity through the
upper part of the
greater sciatic foramen
superior to piriformis
muscle
gluteus medius, gluteus
minimus, and tensor
fasciae lata
Inferior Gluteal Nerve
gluteus maximus
17
Nerve to Quadratus
Femoris
.
Nerve to Obturator
Internus
Posterior
Cutaneous Nerve of
Thigh
Perforating
cutaneous nerve
18
19
20
21
o A minor
. contribution
from S4 and is
formed mainly
by the anterior
rami of S5 and
Co, which
originate
inferiorly to
the pelvic
floor.
o Skin in the
anal triangle
of the perineum
22
Flexors of the hip
Extensors of the knee
Adductors of the thigh
23
Flexors of the knee
.
24
.
Posterior leg
Plantarflexion
Anterior leg
Dorsiflexion
Lateral leg
Eversion
25