lower limb- popliteal fossa and leg Flashcards
what are the boundaries of the popliteal fossa?
SUPERFICIALLY:
- superolaterally by the biceps femoris
- superomedially by the semimembranous, lateral to which is the semitendinosus
- inferolaterally and inferomedially by the lateral and medial heads of gastrocnemius, respectively.
- posteriorly by skin and popliteal fascia
DEEPLY:
- superior boundaries are formed by the diverging medial and lateral supracondylar lines of the femur
- inferior boundary is formed by the soleal line of the tibia
describe the contents of the popliteal fossa
- termination of the small saphenous vein
- popliteal arteries and veins and their branches and tributaries
- tibial and common fibular nerves
- posterior cutaneous nerve of thigh
- popliteal lymph nodes and lymphatic vessels
describe the fascia of the popliteal fossa
- the subcutaneous tissue wh/ overlies the popliteal fossa contains the small saphenous vein and three cutaneous nerves: the oisterior cutaneous nerve of the thigh and the medial and lateral aural cutaneous nerves
- the deep popliteal fascia is a strong sheet, continuous with the fascia lata superiorly and with the deep fascia of the leg. protects the neuromuscular contents
- often pierced by the saphenous vein
what are the branches of the sciatic nerve in the lower leg?
- tibial nerve: supplies soleus, gastrocnemiusm plantaris and popliteaus muscles
- the lateral led and ankle receives some innervation from the media sural cutaneus nerve (a branch of the tibial) and the aural communicating branch of the common fibular nerve
- the smaller more terminal branch of the sciatic is the common fibular nerve which leaves the pop fossa by passing superficial to the lateral head of gastrocnemius
- the skin overlying the popliteal fossa is supplied by the posterior cuteness nerve of thigh
what are the superior and inferior extensor retinaculum in the leg?
- thickenings of the fascia that bind the tendons of the anterior compartment muscles before (superior) and after (inferior) they cross the ankle joint, preventing bowstringing during dorsiflexion
- the superior extensor retinaculcum is a strong, broad band of deep fascia passing from the fibula to the tibia proximal to the malleoli
- the inferior extensor retinaculum is a Y shaped band of deep fascia, attaching laterally to the anterosuperior surface of the calcaneus
name the muscles in the anterior compartment of the leg
- tibialis anterior, extensor digitorum longus, extensor hallisus longus, fibularis tertius
- these are dorsiflexors of the ankle joint
describe the location, attachments, innervation and action of tibialis anterior
- the most medial and superficial dorsiflexor, is a slender muscle that lies against the lateral surface of the tibia
- proximal attachment is to the lateral condyle and superior lateral half of surface of tibia and interosseuous membrane
- distal attachment is medial and inferior surfaces of medial cuneiform and base of 1st metatarsal
- innervation is the deep fibular nerve (L4-5)
- action is dorsiflexion of ankle and inversion of foot
describe the location, attachments, innervation and action of extensor digitorum longus
- most lateral of the anterior leg muscles
- proximal attachment is to the lateral condyle of tibia and superomedial surface of fibula and interosseus membrane
- distal attachment is middle and distal phalanges of lateral 4 digits (tendon splits into 4)
- innervation is deep fibular nerve(L5-S1)
- action is extension of lateral 4 digits and dorsiflexio of ankle
describe the location, attachments, innervation and action of extensor hallucis longus
- a thin muscle that lies deeply between the tibialus anterior and the extensor digitorum longs. rises to the surface in the distal 1/3 of the leg
- proximal attachment is to the middle part of anterior surface of fibula and interosseus membrane
- distal attachment is to the dorsal aspect of base of distal phalynx of great toe
- innervation is deep fibular nerve (L5-S1)
- innervation is extension of great toe and dorsiflexion of ankle
- describe the location, attachmentsm innervation and action of fibularis tertius
- is a separated part of the extensor digitorum longus and proximally these muscles are one and the same
- distally, the tendon of fibularis tertius attaches to dorsum of base of 5th metatarsal
- innervation is deep fibular nerve (L5-S1)
- acton is dorsiflexion of ankle, inversion of foot.
- not always present
what are the nerves in the leg
- saphenous: originates from femoral nerve, descends with femoral vessels through the adductor canal and then descends with great saphenous vein to supply skin on medial side of ankle and foot
- sural: arises from both tibial and common fibular nerves . descends between heads of gastrocnemius and supplies skin on medial side of ankle and foot
- tibial: originates from sciatic nerve and descends through popliteal fossa and supplies posterior muscles of leg and knee joint
- common fibular: forms as sciatic bifurcates in pop fossa and supplies skin on lateral posterior aspect of leg as well as knee joint. divides into superficial and deep fibular nerves
- deep fibular: supplies muscles of anterior leg, dorsum of foot
- superficial fibular: supplies fibularis longs and brevis as well as skin on distal third of anterior surface of leg and dorsum of foot
name the muscles in the lateral compartment of the leg
- fibularis longus, fibularis brevis
describe the location, attachments, innervation and action of fibularis longs
- is the longer and more superficial muscle in the lateral compartment
- proximal attachment is to the head and superior two thirds of the lateral surface of the fibula
- distal attachment is to the base of 1st metatarsal and medial cuneiform
- innervation is superficial fibular nerve
- action is eversion of foot and weak plantarflexion
