14: Posterior Thigh, Poplitea Fossa Flashcards
Posterior thigh common origin (besides short head of biceps femoris)
Ischial tuberosity
Posterior thigh common N
Tibial division of sciatic N
Common A of posterior thigh
Thigh extension, leg flexion
Four muscles of the posterior thigh
Semitendinosus, semimembranosus, biceps femoris, adductor magnus (hamstring portion)
Semitendinosus O and I
O: ischial tuberosity
I: medial surface of tibia
Semimembranosus O and I
O: ischial tuberosity
I: posterior medial condyle of tibia
Distal tendon of semimembranosus - two parts
- One attaches to medial tibial condyle
2. One blends with fascia -> becomes oblique popliteal ligament
Biceps femoris long head O and I
O: ischial tuberosity
I: head of fibular
Biceps femoris short head O and I
O: distal linea aspera
I: head of fibula
Biceps femoris long and short head N
Long head: tibial N
Short head: common fibular N
Adductor magnus hamstring portion O and I
O: ischial tuberosity
I: adductor tubercle on medial epicondyle of femur
Adductor magnus hamstring portion A
Extend thigh
Adductor magnus hamstring portion N
Tibial division of sciatic N
Six muscles involved in boundaries of the popliteal fossa
- Semitendinosus
- Semimembranosus
- Biceps femoris short head
- Biceps femoris long head
- Lateral head gastrocnemius
- Medial head gastrocnemius
Four contents of the popliteal fossa, superficial to deep
- Tibial N
- Popliteal V
- LNs
- Popliteal A and branches
Three branches from the popliteal artery
- Genicular branches
- Anterior tibial A
- Posterior tibial A
Popliteal V formed from union of what?
Anterior tibial + posterior tibial V’s
Where does the popliteal vein form?
Near inferior border of popliteus
What vein terminates into the popliteal V?
Small saphenous V
Where does the sciatic N become tibial and common fibular N’s?
Superior angle of popliteal fossa
Two things supplied by tibial N?
Knee joint, posterior leg muscles
Where is the common fibular N susceptible to injury?
Where it winds around the head/neck of the fibula
What two things does the common fibular N terminate into?
Deep fibular N + superficial fibular N
Three important sural N’s (cutaneous)
Medial sural cutaneous, sural communicating branch, lateral sural cutaneous
What do the sural N’s supply?
Distal posterior leg, lateral aspect of foot and ankle
What two nerves join together to form the sural N?
Lateral + medial sural cutaneous N’s
What is the genicular anastomosis important for?
Circulation bypassing popliteal A (when knee is fully flexed for too long, narrowed popliteal A)
What is supplied by the genicular anastomosis
Articular capsule, ligaments of the knee joint
Seven arteries involved in the genicular anastomosis
- Superior lateral genicular
- Inferior lateral genicular
- Superior medial genicular
- Inferior medial genicular
- Middle genicular
- Descending genicular
- Descending branch of lateral femoral circumflex
Two branches of the descending genicular A
- Muscular terminal branch
2. Saphenous branch
Nerve of the LE most susceptible to injury
Common fibular N
What happens if the common fibular N is injured?
Paralysis of all anterior and lateral crural muscles -> loss of dorsiflexion and eversion -> foot drop
Describe a foot drop
Difficult to heel strike, pt has a high stepping gait/waddling gait, and if the leg is swung strongly forward it will strike with a clop
