Posterior Thigh & Popliteal Fossa Flashcards
What muscles form the 4 borders of the popliteal fossa?
Superomedial: semimembranosus, semitendinosus
Inferomedial: medial head of gastrocnemius
Superolateral: biceps femoris
Inferolateral: lateral head of gastrocnemius
What nerve innervates the skin of the middle posterior thigh?
Posterior femoral cutaneous (S1-S3)
Name the 3 muscles in the posterior thigh
Semimembranosus
Semitendinosus
Biceps femoris
All posterior thigh muscles originate on the _____ (except short head biceps femoris)
Ischial tuberosity
Origin of Short head of biceps femoris
Linea aspera & lateral supracondylar ridge of femur
All posterior thigh muscles are innervated by the… (except short head biceps femoris)
Tibial division of sciatic nerve
Innervation of short head of biceps femoris
Common fibular (peroneal) branch of sciatic nerve
Branches of sciatic nerve
At popliteal fossa:
Tibial division
Common fibular (peroneal) division
Branches of tibial nerve
Sural n
Lateral plantar n
Medial plantar n
Branches of common fibular nerve
Sural n
Deep fibular n
Superficial fibular n
Lateral Sural cutaneous n
The tibial nerve supplies the ____
Posterior leg
The lateral and medial plantar nerves supply the ____
Foot
The deep fibular nerve supplies the ____
Anterior leg
The superficial fibular nerve supplies the ____
Lateral leg
Origin of biceps femoris
- Long: ischial tuberosity
- Short: lateral lip of linea aspera & lateral supracondylar ridge of femur
Insertion of biceps femoris
Head of fibula & lateral condyle of tibia
Innervation of biceps femoris
Long: tibial division of sciatic n
Short: common fibular division of sciatic n
Action of biceps femoris
- flex & laterally rotate leg at the knee
- long head extends the thigh at the hip
Origin & insertion of semitendinosus
O: ischial tuberosity
I: medial surface of proximal tibia
Innervation of semitendinosus
Tibial division of sciatic n
Action of semitendinosus
- flex leg & medially rotate tibia at the knee
- extend thigh at the hip
What structures form the pes anserinus?
Tendons of semitendinosus, sartorius, and gracilis
Origin & insertion of semimembranosus
O: ischial tuberosity
I: posterior aspect of medial condyle of tibia
Innervation of semimembranosus
Tibial division of sciatic n
Action of semimembranosus
- flex leg & medially rotate tibia at the knee
- extend thigh at the hip
Part of the semimembranosus tendon forms the ____
Oblique popliteal ligament
Describe the contents of the popliteal fossa
Popliteal a
Popliteal v
Common fibular n
Tibial n
Describe the Sural nerve
- Sural communicating n (from common fibular n)
- medial Sural cutaneous n (from tibial n)
Join to form Sural n
The Sural nerve supplies…
- skin along distal 2/3 of posterolateral calf
- lateral foot, over 5th digit
Describe variation in the formation of the Sural nerve
Communicating & medial Sural nn join much lower in the leg
Describe the branches of the popliteal artery
- superior lateral & superior medial genicular aa
- middle genicular a
- Sural aa
- inferior lateral & inferior medial genicular aa
What is the passageway for the popliteal artery?
Adductor hiatus
(Above this = femoral a)
The popliteal artery ends by splitting into the ____ and ____
Anterior & posterior tibial aa
The main blood supply to the knee joint is the ____
Popliteal a
The posterior tibial artery gives rise to the ____
Fibular artery
