Posterior Thigh & popliteal fossa Flashcards
How many muscles make up the hamstrings?
3 and a bit - the hamstring portion of abductor Magnus.
What function do the muscles of the posterior thigh perform?
Hip extension and knee flexion.
What nerve innervates the posterior thigh, give its nerve roots.
Sciatic nerve, L4-S3
The short head of biceps femoris differs in innervation from the other muscles in the posterior thigh. How so?
Short head of biceps femoris is innervated by the common peroneal nerve, whilst all the other muscles are innervated by the tibial part of the sciatic nerve.
Where does biceps femoris attach?
Via a tendon to the head of fibula
What is the deep, medial muscle of the posterior thigh?
Semimembranosus. This is covered by semitendinosus.
Where do the muscles of the posterior thigh attach?
Ischial tuberosity.
What can happen in sports when the hamstrings are over worked?
Hamstring injury is unlikely, but ischial tuberosity avulsion can occur due to the strength of these muscles.
Where does semi membranous insert?
Onto the medial epicondyle of the tibia
Which muscle of the posterior thigh inserts onto the posteriomedial tibia?
Semitendinosus.
Describe the root of the sciatic nerve.
This emerges, after passing through the greater sciatic notch, inferior to piriformis. It then passes into the posterior thigh and runs deep to biceps femoris before emerging in the popliteal fossa where it splits into the tibial nerve and the common peroneal nerve.
Name the borders of the popliteal fossa:
Superior medial: semitendinosus
Superior lateral: biceps femoris
Inferior medial: medial head of gastrocnemius
Inferior lateral: lateral head of gastrocnemius
What are the contents of the popliteal fossa?
Popliteal artery, popliteal vein, tibial nerve, common peroneal nerve.
Which vein pierces the popliteal fascia?
The small saphenous vein. It drains into the popliteal vein.
What is bakers cyst?
This is a swelling of the semimembranosus bursa which can occur in osteoarthritis and rheumatoid arthritis.
