Transcript 16-gluteal region

GLUTEAL REGION
Cutaneous nerve supply. 
Fascia. 
Ligaments. 
Muscles. 
Nerves. 
Important Arterial Anastomoses.

CUTANEOUS NERVES
The gluteal region is 
divided into four
quadrants. Each has
its own nerve supply
(1) Upper medial 
Supplied by the 
posterior rami of
the upper three
lumbar and the upper
three sacral nerves.
CUTANEOUS NERVES
(2) Lower 
medial:
Posterior 
cutaneous nerve
of the thigh (S1,2
&3).
CUTANEOUS NERVES
(3) Upper lateral : 
Lateral branches of 
Iliohypogastric (L1)
and Subcostal (T12).
(4) Lower lateral : 
Lateral cutaneous 
nerve of the thigh
(L2&3).
FASCIA
Superficial Fascia : 
Is thick especially in females and 
contains large quantities of fat to
give the characteristic shape of the
buttocks.
Deep Fascia : 
Continuous inferiorly with the deep
fascia of the thigh (fascia lata).

FASCIA
Superiorly it splits 
to enclose the
gluteus maximus
muscle .
It covers the 
gluteus medius and
is attached to the
iliac crest.
LIGAMENTS
1. Iliotibial tract. 
2. Sacrotuberous. 
3. Sacrospinous. 
ILIOYIBIAL TRACT
It is a vertical thickened 
band of the deep fascia on
the lateral side of the thigh.
Attachment : 
Above : tubercle of the iliac
crest.
Below : 
1.Lateral condyle of the 
tibia.
2.Capsule of the knee joint.
3.Patella.



MUSCLES INSERTED
It is reinforced by
fibers from:
1. Superficial (3/4)
of gluteus
maximus.
2. Tensor fascia 
latae.


FUNCTION
Contraction of these two
muscles tighten the tract
and it acts as a splint
for the knee.
It helps to make the 
lower limb works as a
rigid column.

LIGAMENTS
2.Sacrotuberous:
It connects the 
back of the sacrum
to the ischial
tuberosity.
2. Sacrospinous :
It connects the 
back of the sacrum
to the ischial spine.


LIGAMENTS
Function : 
They stabilize the 
sacrum and prevent
its mobility at the
sacroiliac joint by the
weight of the vertebral
column.
MUSCLES
(1) Three Glutei :
Maximus. 
Medius. 
Minimus. 
(2) Tensor Fascia
latae.
(3) Six Lateral 
Rotators.


THREE GLUTEAL MUSCLES
The gluteus maximus 
covers the gluteus
medius and the (6)
lateral rotators.
The gluteus medius 
covers the gluteus
minimus.
The gluteus minimus 
rests immediately upon
the iliac bone.
GLUTEUS MAXIMUS
It is one of the largest, 
thickest and most
powerful muscles of the
body.
It has an extensive 
Origin :
(1) upper part of the 
ileum behind the posterior
gluteal line.
(2) back of the sacrum. 
(3) sacrotuberous 
ligament.
GLUTEUS MAXIMUS
Insertion : 
Superficial ¾ to the 
iliotibial tract.
Deep ¼ to the gluteal 
tuberosity of the
femur.
Nerve supply : 
Inferior gluteal nerve. 
ACTION
(1) It is the main extensor
of the hip.
It is used only when the 
thigh has to be extended
with Force :
(a) Rising from a sitting 
position.
(b) Climbing a hill. 
C. Running. 
It is not used in walking on a
level.


ACTION
(2) A powerful 
lateral rotator of
the hip (when the
thigh is extended)
(3) Its contraction
makes the
iliotibial tract
tense .

INTRAMUSCULAR INJECTION
The great thickness of 
gluteus maximus makes
it ideal for intramuscular
injection.
The injection should be 
given on the upper
outer quadrant of the
buttock to avoid injury
of the following nerves:
sciatic, tibial,
common peroneal and
inferior gluteal.
BURSAE RELATED
Three bursae lie under the
gluteus maximus :
1. A bursa between the 
lower edge of the muscle
and the ischial tuberosity.
2. A large bursa separating
the muscle from the greater
trochanter.
3. A large bursa between 
the aponeurotic part of the
muscle and vastus lateralis.


GLUTEUS MEDIUS
It is a large thick 
powerful fan
shaped muscle.
Origin : 
A large area 
between the iliac
crest and the
middle gluteal line.
GLUTEUS MEDIUS
Insertion : 
In the postero superior 
angle of the greater
trochanter and the
oblique line on its lateral
surface.
GLUTEUS MEDIUS
Nerve supply : 
Superior gluteal 
nerve.
Action : 
1. Abduction of the 
thigh.
2. Medial rotation 
of the thigh (anterior
fibers ).
GLUTEUS MEDIUS
In standing, if the support of 
one limb is suddenly
removed, the gluteus medius
of the other side contracts
to prevent the pelvis from
falling on the unsupported
side.
The alternative action of the 
gluteus medius on both sides
is responsible for keeping the
pelvis level during walking.
Without the gluteus medius 
of both sides the gait
GLUTEUS MINIMUS
It is a fan shaped 
muscle that lies deep
to the anterior part of
gluteus medius.
Origin : 
From the ilium 
between the middle
and inferior gluteal
lines.
GLUTEUS MINIMUS
Insertion : 
Anterior surface of
greater trochanter.
Nerve supply : 
Superior gluteal 
nerve.
Action : 
same as gluteus 
medius.

TENSOR FASCIA LATAE
It is a short thick muscle
that lies at the junction
of the gluteal region and
the upper part of the
front of the thigh.
Origin : 
From the extreme 
anterior part of the iliac
crest (just behind the
anterior superior iliac
spine).

TENSOR FASCIA LATAE
Insertion : 
In the iliotibial tract.
Nerve supply: 
Superior gluteal 
nerve.

TENSOR FASCIA LATAE
Action : 
It tightens the knee so 
that in walking the knee
can take the weight of the
body while the other foot
is off the ground.
The extension of the knee
is made through
tightening of the iliotibial
tact with the help of
gluteus maximus.

SIX LATERAL ROTATORS
Piriformis. 
Obturator 
internus.
Gemelli (superior
and inferior ).
Obturator 
externus.
Quadratus 
femoris.

SIX LATERAL ROTATORS
These muscles 
pass behind the
hip joint.
They lie below and 
behind gluteus
minimus.
They are covered 
by gluteus
maximus.
ORIGIN
1. Piriformis 
Inside the pelvis mainly 
from the middle (3)
pieces of the anterior
surface of the sacrum.
It leaves the pelvis 
through the GSF which it
fills almost completely.
ORIGIN
2. Obturato 
Internus:
Inside the pelvis 
from the obturator
membrane and the
surrounding bones.
It leaves the pelvis
through the LSF.

ORIGIN
3 & 4. Gemellus superior
and Gemellus inferior :
From the upper and lower 
margins of the LS Notch
respectively.
They are inserted into the 
tendon of obturator internus.
5. Quadratus femoris : 
From the ischial tuberosity. 

SIX LATERAL ROTATORS
Insertion : 
The tendons are 
inserted into the
greater trochanter.
Action : 
Lateral rotation of
the hip joint.

SIX LATERAL ROTATORS
Nerve supply : 
Each of these 
muscles (Except
obturator
externus) has its
own nerve supply
from the sacral
plexus or from the
sacral nerves.
ORIGIN
6. Obturator externus 
Outside the pelvis from 
the obturator membrane
and the medial and
lower margins of the
obturator foramen.
It is inserted in the 
trochanteric fossa.
NERVES
1. Sciatic nerve. 
2. Posterior cutaneous 
nerve of thigh.
3. Superior and Inferior 
Gluteal nerves.
4. Nerve to Quadratus 
Femoris.
5. Nerve to Obturator 
Internus.
6. Pudendal nerve. 
SCIATIC NERVE
It is the largest 
nerve in the body.
It is the larger of 
the two terminal
branches of the
sacral plexus.
It is flat and broad
near its origin and
becomes rounded
downwards.

SCIATIC NERVE
It is composed of two 
components :
(a) Tibial nerve : 
It arises from the ventral 
divisions of all components
of the sacral plexus.
(b) Common peroneal 
verve :
It arises from the dorsal 
divisions of all components
of the sacral plexus.
COURSE
It leaves the pelvis 
through the lower part of
the GSF below the
piriformis.
As it descends it lies on:
1.Root of ischial spine. 
2.Gemelli. 
3.Obturator internus. 
4.Quadratus femoris. 
5.Adductor magnus. 

COURSE
It is related posteriorly to :
1.Posterior cutaneous nerve
of the thigh.
2.Gluteus maximus. 
It enters the back of the 
thigh by passing deep to the
long head of biceps femoris.
Branches : 
Usually it has No branches in
the gluteal region.



TERMINATION
About the middle of
the thigh it divides
into its terminal
branches :Tibial and
Common Peroneal.

POSTERIOR CUTANEOUS N. OF
THE THIGH
ORIGIN : 
Sacral plexus. 
COURSE : 
It leaves the pelvis through
the lower part of the GSF
below piriformis.
It descends on the posterior
surface of the sciatic nerve
till the popliteal fossa.


POSTERIOR CUTANEOUS N. OF
THE THIGH
BRANCHES : 
1. Gluteal : to the lower 
medial quadrant of the
buttock.
2. Perineal : to the skin 
of the back of scrotum (or
labia majora).
3. Cutaneous : to the 
back of the thigh and
upper leg.
SUPERIOR GLUTEAL NERVE
ORIGIN : 
From the sacral 
plexus (L4,5 & S1).
COURSE : 
It leaves the pelvis 
through the upper
part of the greater
sciatic foramen above
piriformis.
It passes between 
gluteus medius and
minimus.
SUPERIOR GLUTEAL NERVE
BRANCHES 
It gives motor supply
to:
1. Gluteus medius. 
2. Gluteus minimus. 
3. Tensor fascia latae.


INFERIOR GLUTEAL NERVE
Origin: 
Sacral plexus (L5, S1 &S2). 
Course : 
It leaves the pelvis through 
the lower part of the (GSF)
below piriformis.
Branches: 
It gives motor supply to : 
Gluteus maximus. 
NERVE TO QUADRATUS
FEMORISN
It arises from the sacral 
plexus.
It leaves the pelvis 
through the lower part of
the GSF below piriformis.
It supplies : 
(1) Quadratus femoris. 
(2) Inferior gemillus. 
PUDENDAL N. & N. TO
OBTURATOR INTERNUS
Both arise from the 
sacral plexus.
They Leave the pelvis 
through the lower part of
GSF below piriformis.
They reenter the pelvis 
through the LSF with the
pudendal vessels by
crossing the ischial spine.
PUDENDAL N. & N. TO
OBTURATOR INTERNUS
Nerve to obturator 
internus
Supplies : 
1. Obturator internus. 
2. Superior gemellus. 
Pudendal Neve 
Supplies the structures 
in the perineum.
SUPERIOR & INFERIOR
GLUTEAL ARTERIES
They arise from the internal 
iliac artery.
They leave the pelvis through
the GSF above and below the
piriformis muscle respectively
in company with the
corresponding nerves.
They distribute into many 
branches and share in the
anastomoses in the gluteal
region and back of the thigh.

TROCHANTERIC ANASTOMOSIS
Position : 
Near the trochanteric fossa. 
Arteries sharing : 
(1) Superior gluteal. 
(2) Inferior gluteal. 
(3) Medial circumflex femoral.
(4) Lateral circumflex femoral.
Function : 

It is the main source of 
arterial supply of the head
of the femur.

CRUCIATE ANASTOMOSIS
Position : 
On the upper part of the back 
of the thigh.
Arteries sharing : 
(1) Inferior gluteal. 
(2) Medial circumflex femoral. 
(3) Lateral circumflex femoral. 
(4) First perforating. 
Function : 
It provides connection between 
internal iliac and femoral
arteries.