Posterior Thigh And Popliteal Fossa Flashcards
What is the common proximal attachment (origin) of the posterior thigh muscles?
Ischial tuberosity (Except short head of biceps femoris)
What is the common innervation for posterior thigh muscles?
Tibial division of sciatic nerve
Except short head of biceps femoris
What are the functions of posterior thigh muscles?
Thigh extension (except short head of biceps femoris) Leg flexion (all four muscles)
What is the unique characteristic of the semitendinosus muscle?
Long cordlike tendon that begins 2/3 of the way down the thigh
What is the insertion site for semitendinosus?
Medial surface of superior aspect of tibia
What is the insertion site for semimembranosus?
Posterior part of medial condyle of tibia
The distal tendon of the semimembranosus muscle divides into two parts. What are those two divisions?
To medial tibial condyle
Part blends with popliteal fossa and becomes oblique popliteal ligament (reinforces the intercondylar part of joint capsule)
What is the function for the short head of biceps femoris?
Only flexes leg
What is the short head of biceps femoris innervated by?
Common fibular division of sciatic nerve
What is the origin of short head of biceps femoris?
Distal lateral lip of linea aspera
What is the common insertion for both short and long heads of the biceps femoris?
Head of the fibula
What is the insertion site for the adductor magnus (hamstring portion)
Adductor tubercle on the medial epicondyle of the femur
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 gastrocnemius
What are the contents of the popliteal fossa from superficial to deep?
Nerves
Popliteal vein, LNs and branches
Popliteal artery and branches
What is the deepest structure in the popliteal fossa?
Popliteal artery
When does the femoral artery become the popliteal artery?
After passing through the adductor hiatus
What does the popliteal artery run close to?
The knee joint capsule and gives rise to genicular branches
What do the genicular branches of the popliteal artery participate in?
Formation of the genicular anastomosis
Why is the genicular anastomosis important?
It is an important collateral circulation bypassing the popliteal artery when the knee is fully flexed too long or when popliteal vessels are narrowed/occluded
What do genicular branches of the popliteal artery supply?
Articular capsule and ligaments of the knee joint
Which arteries are involved in the genicular anastomosis?
Branches from the descending genicular artery
Superior and inferior lateral genicular, superior and inferior medial genicular and middle genicular arteries
Anterior tibial recurrent A
Descending genicular from lateral circumflex femoral A
What are the terminal branches of the popliteal artery?
Anterior and posterior tibial arteries
The popliteal vein is formed by the union of what?
Anterior and posterior tibial veins usually near the inferior border of the popliteus muscle
Which vein terminates into the popliteal vein?
Small saphenous vein
Where does the popliteal vein lie?
Lies superificial to and in same fibrous sheath as popliteal artery
When does the popliteal vein become the femoral vein?
After traversing the adductor hiatus
Where does the sciatic nerve usually end?
At superior angle of popliteal fossa where it divides into the tibial and common fibular nerves
What is the distribution of the tibial nerve?
Superficial and deep posterior leg muscles
Knee joint
Where does the common fibular nerve leave the popliteal fossa?
By passing superficial to the lateral head of gastrocnemius then winds around the head and neck of the fibula (susceptible to injury)
Where does the common fibular nerve terminate?
Deep to fibularis longs into deep and superficial fibular nerves
What is the sural nerve composed of?
Medial sural cutaneous nerve from the tibial nerve
Sural (or fibular) communicating branch from the common fibular nerve or the lateral sural cutaneous nerve
What cutaneous nerve is present in the popliteal fossa?
Sural nerve
What nerve is present in the popliteal fossa?
Sciatic nerve
What structure does the sural nerve run with?
Runs inferiorly with small saphenous vein
What does the sural nerve supply?
Distal posterior aspect of the leg and lateral aspect of ankle and foot
In what population are hamstring injuries common in and what are they often the result of?
Common in individuals who run and/or kick hard
Often results from inadequate warm up before activity
What causes the tear in hamstring injuries?
The violent muscular exertion required to excel in these sports may tear part of the proximal tendinous attachments of the hamstrings to the ischial tuberosity
Often so painful that the person falls and writhes in pain when they move or stretch
What occurs with complete section of the sciatic nerve?
The leg is useless because extension of the hip is impaired as is flexion of the leg
All ankle and foot movements are also lost
What occurs with incomplete section of the sciatic nerve (e.g. from stab wounds)?
May involve the inferior gluteal and/or posterior femoral cutaneous nerve
Recovery from lesion of the sciatic nerve is slow and usually incomplete
What can occur with wounds or surgery to the medial side (danger side) of the buttocks?
It may injure the sciatic nerve and its branches to the hamstrings on the posterior thigh
Paralysis of these muscles results in impairment of thigh extension and leg flexion
What is the “side of safety” for the sciatic nerve?
Operations or wound on the lateral side usually will not injure the sciatic nerve
