Download The thigh: blood supply

The thigh:
blood supply
Lecture 6
Femoral Triangle
The femoral triangle is a
triangular depressed area situated
in the upper part of the medial
aspect of the thigh just below the
inguinal ligament. Its boundaries
are as follows:
Superiorly: The inguinal
ligament
Laterally: The sartorius muscle
Medially: The adductor longus
muscle
Its floor is formed from lateral
to medial by the iliopsoas, the
pectineus, and the adductor longus.
Its roof is formed by the skin and
fasciae of the thigh.
Contents of the femoral triangle
The femoral triangle contains the terminal part of the femoral nerve and its
branches, the femoral artery and its branches, the femoral vein and its tributaries,
and the deep inguinal lymph nodes.
Blood supply of the thigh
Three arteries enter the
thigh:
1. the femoral artery,
2. the obturator artery,
3. the inferior gluteal artery.
Of these, the femoral
artery is the largest and
supplies most of the lower
limb.
The three arteries
contribute to an anastomotic
network of vessels around the
hip joint.
Femoral artery
The femoral artery is the
continuation of the external iliac
artery and begins as the external iliac
artery passes under the inguinal
ligament to enter the femoral triangle
on the anterior aspect of the upper
thigh.
The femoral artery is palpable in
the femoral triangle just inferior to
the inguinal ligament midway
between the anterior superior iliac
spine and the pubic symphysis.
Branching
A cluster of four small branches
originate from the femoral artery in
the femoral triangle:
- superficial epigastric artery,
- superficial circumflex iliac
artery,
- superficial external pudendal
artery,
- deep external pudendal artery.
They supply cutaneous regions of
the upper thigh, lower abdomen, and
perineum.
Adductor canal
The femoral artery passes
vertically through the femoral
triangle and then continues down
the thigh in the adductor canal.
The adductor canal is an
intermuscular cleft situated on the
medial aspect of the middle third of
the thigh beneath the sartorius
muscle.
It begins above at the apex of the
femoral triangle and ends below at
the opening in the adductor magnus
adductor hiatus.
In cross section it is triangular,
having an anteromedial wall, a
posterior wall, and a lateral wall.
Adductor canal
The anteromedial wall is
formed by the sartorius muscle and
fascia.
The posterior wall is formed
by the adductor longus and
magnus.
The lateral wall is formed by
the vastus medialis.
The femoral artery leaves the
canal by passing through the
adductor hiatus in the adductor
magnus muscle and becomes the
popliteal artery behind the knee.
Deep artery of thigh
The largest branch of the
femoral artery in the thigh is the
deep artery of thigh (profunda
femoris artery).
Itoriginates from the lateral
side of the femoral artery in the
femoral triangle and is the major
source of blood supply to the
thigh.
The deep artery of thigh passes
through the middle compartment
of the thigh eventually connecting
with branches of the popliteal
artery behind the knee.
Deep artery of thigh
Branches
The lateral circumflex femoral artery normally originates proximally
from the lateral side of the deep artery of thigh, but may arise directly from
the femoral artery.
The medial circumflex femoral artery normally originates proximally
from the posteromedial aspect of the deep artery of thigh.
The first perforating arteries originates above the adductor brevis
muscle, the second originates anterior to the muscle, and the third originates
below the muscle.
All three penetrate through the adductor magnus near its attachment to
the linea aspera to enter and supply the posterior compartment of thigh.
Perforating arteries
Obturator artery
The Obturator artery originates
as a branch of the internal iliac artery
in the pelvic cavity and enters the
medial compartment of thigh through
the obturator canal.
As it passes through the canal, it
bifurcates into an anterior branch
and a posterior branch
Supply the medial compartment of
the thigh, femur and obturator
externus muscle
Veins of the thigh
Veins in the thigh consist of
superficial and deep veins.
Deep veins generally follow the
arteries and have similar names. They
are located within the muscle fascia
which allows a high volume and
pressure of blood to pass through the
veins.
They account for approximately
90-95% of venous blood return to the
heart.
Deep veins can form deep vein
thrombosis, or DVT, which is a
dangerous clot in the deep system.
Superficial veins
Superficial veins are in the
superficial fascia, interconnect with
deep veins, and do not generally
accompany arteries.
There are two main superficial
veins on the lower limb:
 Vena saphena magna (great
saphenous vein);
 Vena saphena parva (small
saphenous vein).
In the subinguinal region, fascia
lata has an oval opening called
saphenous opening (or saphenous
hiatus).
Above, lateral and below it has a
sharp border called falciform
margin.
Fascia lata: saphenous opening
The saphenous opening transmits
the great saphenous vein and other
smaller vessels (like superficial
epigastric artery and superficial external
pudendal artery).
The great saphenous vein runs in
the medial side of the thigh and inflow to
the femoral (deep) vein in the femoral
triangle.
The vena saphena parva runs along
the posterior aspect of the leg, passes
between the heads of the gastrocnemius
muscle, and drains into the popliteal
vein, approximately at or above the level
of the knee joint.