popliteal fossa and posterior leg

Question 1

what is the popliteal fossa bounded by?

Answer 1

muscle - semitendinosus/semimembranosus (superomedially)
biceps femoris (superolaterally)
medial and lateral heads of gastrocnemius (inferiorly)

Question 2

where does small saphenous vein end?

Answer 2

in fossa by passing through the deep fascia in the median plane of the limb to drain into the popliteal vein

Question 3

neuromuscular bundle in median plane of fossa

Answer 3

superficial to deep: tibial nerve (from sciatic), popliteal vein (continuation of posterior tibial veins), popliteal artery (continuation of femoral artery)
popliteal lymph nodes are located along the vein in the fossa

Question 4

where does sciatic nerve divide?

Answer 4

superior apex of popliteal fossa into tibial nerve and common fibular nerve

Question 5

tibial nerve descends how?

Answer 5

vertically through fossa

Question 6

common fibular nerve descends how?

Answer 6

lateral border of fossa, deep to biceps femoris tendon leaving the fossa between the tendon and the lateral head of gastrocnemius to reach the fibular neck, which it winds around prior to dividing into deep and superficial fibular nerves

Question 7

what are the sural nerves?

Answer 7

located in superficial popliteal fossa and supply skin and fascia
each tibial and common fibular nerves give rise to a rural cutaneous branch - the medial rural cutaneous (tibial) and lateral (common fibular)

Question 8

how does fibular nerve get compression injury

Answer 8

neck of fibula
can lead to abnormal sensation
damaged in fractures to fibular neck

Question 9

popliteal pulse

Answer 9

deep location of popliteal artery and the presence of popliteal fat can make it difficult to palpate the popliteal pulse
flex knee to approx 30 degrees and relax hamstring muscles will aid the exam

Question 10

what is the vehicular anastomoses?

Answer 10

provides collateral blood to structures of knee joint, leg, and foot
important when knee is maximally flexed which can lead to partial occlusion of popliteal artery

Question 11

superficial group of muscles in posterior leg

Answer 11

gastrocnemius, soles, and plantaris

Question 12

deep muscles of posterior leg

Answer 12

popliteus, flexor hallucis longus, flexor digitorum longus, and tibialis posterior

Question 13

what do deep muscles of posterior leg do?

Answer 13

plantar flex the ankle and toes

tibialis posterior assists tibilalis anterior (of the anterior compartment of leg) with inversion of the foot

Question 14

what passes through posterior compartment to reach sole of foot, how, and anterior to posterior

Answer 14

tibialis posterior, flexor digitorum longus, posterior tibial artery, tibial nerve and the tendon of flexor hallucis longus leave the compartment to reach the sole of the foot by passing posterior to the medial malleolus and deep to the flexor retinaculum (Tom, Dick, ANd Harry)

Question 15

heads of gastrocnemius

Answer 15

attach distally to calcaneus via achilles tendon and proximally to their respective femoral condyle
weak knee flexor and powerful ankle plantar-flexor (push of phase in walking/running)

Question 16

soles

Answer 16

attaches to neck of fibula and the sole line of tibial, distal to calcaneus via achilles

Question 17

ankle jerk reflex

Answer 17

deep tendon reflex
supine patients lower limb externally rotated, knee flexed and ankle dorsiflexed with gastrocnemius and soles relaxed
calcanea tendon is struck with the tendon hammer just proximal to its interstion in the calcaneus

Question 18

branches of popliteal artery

Answer 18

divides after fossa into anterior and posterior tibial arteries, fibular artery is a branch of the posterior tibial artery
fibular artery is branch of the posterior tibial artery

Question 19

anterior tibial artery

Answer 19

pierces the interosseous membrane to supply anterior compartment of leg

Question 20

posterior tibial artery

Answer 20

supplies posterior compartment
runs with tibial nerve
passes posterior to medial malleolus (posterior tibial pulse is taken) and deep to the flexor retinaculum
divides in foot to medial and lateral plantar arteries

Question 21

fibular artery

Answer 21

branches from posterior tibial artery in the proximal half of the compartment
descends in compartment on the posterior inter muscular septum and sends perforating branches through the septum to supply the lateral compartment of leg

Question 22

what does popliteus do?

Answer 22

weakly flexes knee and unlocks it by rotating femur 5 degrees on fixed tibia; medially rotates tibia of unplanted limb

Question 23

what does flexor hallucis longus do

Answer 23

flexes great toe at all joints’ weakly plantar flexes ankle; supports medial longitudinal arch of foot

Question 24

what does flexor digitorum longus do?

Answer 24

flexes lateral four digits; plantar flexes ankle; supports longitudinal arches of foot

Question 25

what does tibialis posterior do?

Answer 25

plantar flexes ankle; inverts foot

Question 26

what does soleus do?

Answer 26

plantar flexes ankle, independent of position of knee; steadies leg on foot

Question 27

what does plantaris do?

Answer 27

weakly assists gastrocnemius in plantar flexing ankle