Download CA I - Dissection Lab 1

ANTERIOR / MEDIAL THIGH DISSECTION GUIDE
Lower Extremity Lab 1
Mark W. Cornwall, PhD, PT, CPed
1. To remove the skin from the anterior and medial aspects of the thigh, make your first cut from
the anterior superior iliac spine (ASIS) along the inguinal ligament to the pubic tubercle. Next
make a cut from the midpoint of the inguinal ligament (starting from the first cut described
above) to the tibial tubercle. Make your final cut starting from the tibial tubercle,
circumferentially, to the lateral aspect of the tibial and then to the medial aspect of the tibial.
2. Once you have completed your incisions, now pull the skin back so that you can see the anterior
and medial aspects of the thigh. As you observe the anterior thigh, first dig through the fatty
tissue to identify the greater saphenous vein. Note that the greater saphenous vein travels in a
distal to proximal direction on the medial aspect of the thigh. Once you have identified the
greater saphenous vein, you should then clean all of the fatty tissue away from the fascia late.
3. Now examine the fascia lata, which is the connective tissue layer that covers and binds together
the contents of the thigh. Observe the ilio-tibial band that is specialized thickening of the fascia
lata. The muscles that insert into the fascia lata are tensor fascia lata and gluteus maximus.
4. Depending on the embalming procedure used, the saphenous opening may still be intact. The
saphenous opening serves as the entrance point for the greater saphenous vein to pass from
outside the fascia lata to within so that it can connect to the femoral vein. Although they have
already been removed, the region of the saphenous opening contains large numbers of lymph
nodes.
5. Beginning at the saphenous opening, cut the fascia lata down the midline of the thigh to
approximately 6 centimeters above the patella. Using a probe, separate the fascia from the
underlying quadriceps muscle group and observe the anterior compartment formed by the fascia
lata.
6. At the level of the saphenous opening and just above the patella, cut the fascia perpendicular to
the previously made midline cut and remove the fascia to expose the muscles, nerves, and
vessels of the anterior and medial thigh.
7. Relocate the saphenous vein at its entrance point into the femoral vein. The femoral vein will
not be clearly seen as it is contained in the femoral sheath. The femoral sheath serves as a
protective pouch, developed from various abdominal facial layers, that guides the femoral artery
and vein from the pelvic cavity into the thigh.
8. The femoral sheath is divided into three compartments. The lateral compartment contains the
femoral artery; the middle compartment the femoral vein, and the medial compartment that
contains the femoral canal. The femoral canal contains lymph nodes and at the most superior
aspect is located the femoral ring. The ring is comprised of dense circular connective tissue that
if weakened can allow abdominal contents to enter the canal. This is termed a femoral hernia.
Identify the three components of the femoral sheath and then remove and clean the region to
expose the femoral artery and vein.
9. The femoral artery bisects the femoral triangle. The femoral triangle is formed by the inguinal
ligament (superior border), the sartorius muscle (lateral border), and the adductor longus muscle
(medial border). Identify the three borders of the femoral triangle.
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Department of Physical Therapy and Athletic Training
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10. The first major branch of the femoral artery is the profunda or deep femoral artery. In most
cases, the medial and lateral circumflex arteries will branch from the profunda femoral. The
medial and lateral circumflex arteries each have 3 and 4 branches, respectively. Both the medial
and lateral contribute to the hip joint arterial anastomoses, while the lateral also contributes to the
knee complex anastomoses. Identify the lateral and medial circumflex arteries, including as
many branches as possible.
11. The femoral nerve enters the thigh just lateral to the femoral sheath. Since the nerve divides into
multiple small branches after passing under the inguinal ligament it is technically considered to
terminate in the femoral triangle. Two branches of the femoral nerve, the nerve to the vastus
medialis and the saphenous nerve (sensory) leave the triangle to travel more distally down the
thigh.
12. Now identify and then review the origins, insertions, innervations and actions of the following
muscles of the anterior thigh:
• Quadriceps
a. rectus femoris
b. vastus medialis
c. vastus lateralis
d. vastus intermedius
• Sartarius
• Iliopsoas (forms lateral floor of femoral)
• Tensor Fascia Lata
13. As the femoral artery and vein leave the femoral triangle, they enter the adductor or Hunters’
canal. The adductor canal is formed by the sartorius (medial wall), the adductor longus/magnus
(posterior wall) and the vastus medialis (anterior wall). Identify the walls of the adductor canal.
NOTE: The sartorius may have to be cut at its midpoint in order to completely expose the canal.
Also observe how the femoral artery and vein pass through the hiatus formed by the adductor
magnus muscle. After passing through the hiatus, the femoral artery and vein now enter the
popliteal fossa and thus, are now called the popliteal artery and vein.
14. Now identify and review the origins, insertions, innervations and actions of the following
muscles of the medial thigh:
1)
Pectineus (forms medial floor of femoral)
2)
Adductor longus
3)
Adductor brevis (directly beneath the longus)
4)
Adductor magnus
5)
Gracilis
14. Identify the anterior branch of obturator nerve by cutting the adductor longus at its midpoint. As
you reflect the adductor longus and carefully clean the fascia over the adductor brevis, observe
the thin yellow colored cords that are exposed. These cords are the anterior branches of the
obturator nerve.
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You should be able to identify the following structures on a cadaver or a skeleton.
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Greater saphenous vein
Fascia lata
Ilio-tibial band
Saphenous opening
Vastus Medialis Obliqus
Vastus Lateralis Obliqus
Vastus Intermedialis
Rectus Femorus
Femoral sheath
Lateral compartment
Medial compartment
Femoral canal
Femoral artery
Inguinal ligament
Sartorius muscle
Adductor longus
Profunda or deep femoral artery
Medial and lateral circumflex arteries
Femoral nerve
Nerve to the vastus medialis
Saphenous nerve
Sartarius
Iliopsoas
Tensor fascia lata
Adductor or hunters’ canal.
Adductor longus
Adductor magnus
Hiatus formed by the adductor magnus muscle.
Pectineus
Gracilis
Anterior branch of obturator nerve
On the skeleton or other bony materials, identify the following landmarks:
a) ASIS
b) AIIS
c) Pubic tubercle
d) Greater Trochanter
e) Lesser Trochanter
f) Lateral condyle & epicondyle
g) Medial condyle & epicondyle
h) Adductor tubercle
i) Linea aspera
j) Patella
k) Tibial tubercle (or tuberosity)
PT525-Clinical Anatomy I
Department of Physical Therapy and Athletic Training
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