Posterior Thigh and Popliteal Fossa

Question 1

Biceps Femoris (long and short heads)

Answer 1

Origin:
Long head: ischial tuberosity

Short head: linea aspera
and lateral supracondylar line of femur

Insertion:
Lateral side of head of fibula; tendon is split at this site by fibular collateral ligament of knee

Innervation:
Long head: tibial division of sciatic nerve (L5, S1, S2)

Short head: common fibular
division of sciatic nerve (L5, S1, S2)

Action:
Flexes knee joint and rotates it laterally when knee is flexed; extends hip joint (e.g., when starting to walk)

Question 2

Semitendinous Muscles

Answer 2

Origin:
Ischial tuberosity

Insertion:
Medial surface of superior part of tibia

Innervation:
Tibial division of sciatic nerve (L5, S1, S2)

Action:
Extend hip joint; flex knee joint and rotate the leg medially when knee is flexed; when hip and knee are flexed, can extend trunk

Question 3

Semimembranosus Muscle

Answer 3

Origin:
Ischial tuberosity

Insertion:
Posterior part of medial condyle of tibia; reflected attachment forms oblique popliteal ligament (to lateral femoral condyle)

Innervation:
Tibial division of sciatic nerve (L5, S1, S2)

Action:
Extend hip joint; flex knee joint and rotate the leg medially when knee is flexed; when hip and knee are flexed, can extend trunk

Question 4

Gastrocnemius (Lateral and Medial Head)

Answer 4

Origin:
Lateral head: lateral aspect of lateral condyle of femur

Medial head: popliteal surface of femur, superior to medial condyle

Insertion:
Posterior surface of calcaneus via calcaneal tendon

Innervation:
Tibial nerve (S1, S2)

Action:
Plantarflexes ankle when knee is extended; raises heel during walking; and flexes knee joint

Question 5

Popliteal Artery

Answer 5

origin:
Femoral Artery

Femoral artery becomes Popliteal artery after passing through the Adductor Hiatus

Question 6

Popliteal Fossa

Answer 6

Boundary:
Superior (From Lateral to Medial):
Biceps Femoris (Short/Long), Semitendinosus tendon, semimembranosus.

Inferior (lateral to medial)
Lateral head of Gastrocnemius and Medial head of Gastrocnemius.

Roof:
Skin and Popliteal fascia

Floor:
Popliteal surface of the femur, posterior capsule of the knee joint, and popliteus fascia covering the popliteus muscle.

Contents:
Termination of small saphenous vein
Popliteal artery and vein
Tibial and common fibular nerves
Posterior cutaneous nerve of the thigh
Popliteal lymph nodes and vessels
Fat

Question 7

Femoral Triangle

Answer 7

Boundaries:
Superior - Inguinal Ligament
Inferolateral - Sartorius
Inferomedial- Adductor Longus

Contents:
Femoral Nerve, Artery, Vein (Lateral to medial)