Posterior thigh and popliteal fossa Flashcards
Semitendinosus m. origin, insertion, action, innervation
O: ischial tuberosity
I: Pes anserinus
A: Extend thigh, flex leg, medially rotate leg when flexed
Innervation: Tibial division (L4-S3) of sciatic nerve
What 3 muscles insert on to the pes anserinus and what innervates them?
Sartorius - femoral nerve
Gracilis - obturator nerve
Semitendinosus - tibial division of the sciatic nerve
Semimembranosus m. origin, insertion, action, innervation
O: ischial tuberosity
I: posterior aspect of medial tibial condyle
A: Extend thigh and flex leg
Innervation: tibial division of the sciatic nerve
What happens to the semimembranosus tendon?
One half connects muscle to posterior medial tibial condyle; one half leaves the medial tibial condyle to run supero-laterally across the backside of the knee to reinforce the intercondylar capsule of the knee
What makes up the biceps femoris?
Long head and short head
Long head origin, insertion, action and innervation
O: ischial tuberosity
I: Lateral aspect of fibular head
A: Extend thigh, flex and laterally rotate leg
Innervation: tibial division of the sciatic nerve
Short head origin, insertion, action and innervation
O: Linea aspera and lateral supracondylar line of posterior femur
I: Lateral aspect of fibular head
A: Flex and laterally rotate leg
Innervation: common fibular division of sciatic nerve
Name the muscles in the posterior thigh
Biceps femoris (long and short head), semitendinosus, semimembranosus
How does the adductor magnus help the posterior thigh?
The hamstring portion origin: ischial tuberosity
I: Adductor tubercle on medial tibial epicondyle
Innervation: tibial division of the sciatic nerve
Extends the thigh as well
What is the popliteal fossa?
Diamond shaped region of posterior knee
What is the superomedial boundary of the popliteal fossa?
Semitendinosus and semimembranosus
What is the superolateral boundary of the popliteal fossa?
Biceps femoris
What is the inferolateral boundary of the popliteal fossa?
Lateral head of gastrocnemius
What is the inferomedial boundary of the popliteal fossa?
Medial head of the gastrocnemius
What are the contents of the popliteal fossa?
Nerves, popliteal vein, lymph nodes and branches, popliteal artery and branches
Going from superficial to deep within the popliteal fossa, what is the order of what you will find?
Nerves
Popliteal VEIN and branches and lymph nodes
Popliteal ARTERY and branches
What is the popliteal artery?
Continuation of the femoral artery once it passes through the adductor hiatus
What does the popliteal artery do?
Gives rise to genicular branches close to the knee joint capsule
List the functions of the genicular branches
Genicular anastomosis and supplies articular capsule and ligaments in the knee
What is the purpose of the genicular anastamosis
To supply blood to knee/lower limb if the femoral/popliteal artery is occluded or if the knee is flexed for too long
Name the big players in genicular anastamosis
Superior lateral genicular A. Inferior lateral genicular A. Superior medial genicular A. Inferior medial genicular A. ** Descending branch of lateral circumflex femoral A.
What is the role of the descending branch of lateral circumflex femoral A. in genicular anastamosis?
It participates in the cruciate anastamosis so it can bring blood down the thigh to the knee if the femoral A. is occluded or severed
How does the popliteal artery terminate?
It divides into the anterior tibial artery and posterior tibial artery
What forms the popliteal vein?
Union between anterior and posterior tibial veins at inferior border of popliteus muscle
What terminates into popliteal vein?
Small saphenous vein - becomes femoral vein after adductor hiatus
Nerves in popliteal fossa?
Tibial division and common fibular division of sciatic nerve
Where does the sciatic nerve branch?
Superior angle of popliteal fossa
What does the tibial division nerve innervate?
Superficial and deep muscles in posterior leg, knee joint
What does the common fibular nerve do?
Leaves popliteal fossa superior to lateral head of gastrocnemius
Winds around neck and head of fibula and is prone to injury
Terminates into deep fibular nerve and superficial fibular nerve
What is the cutaneous nerve of distal posterior aspect of leg and lateral ankle/foot
Sural nerves
List sural nerves
Medial sural cutaneous nerve, sural communicating branch, lateral sural cutaneous nerve, common fibular nerve
