Dissection 4

Question 1

what are the borders of the popliteal fossa?

Answer 1

superomedial = sacrotuberous and sacromembranous muscles
superolateral = biceps femoris
inferomedial and lateral = gastrocnaemius
floor = capsule of the knee joint, distal femur and proximal tibia/popliteus muscle
roof = popliteal fascia

Question 2

what pierces the popliteal fascia?

Answer 2

short saphenous vein

sural nerve

Question 3

what are the 4 main nerves in the popliteal fossa?

Answer 3

tibial
common fibular
sural
posterior femoral cutaneous

Question 4

where does the tibial nerve originate?

Answer 4

where the sciatic nerve bifurcates into the tibial and common fibular nerve at the superior angle of the popliteal fossa
tibial = larger, medial branch

Question 5

describe the path of the tibial nerve

Answer 5

originates at the superior angle of the popliteal fossa
passes through the fossa inferiorly
exits deep to the plantaris muscle
enters posterior compartment of the leg

Question 6

what does the tibial nerve supply?

Answer 6

soleus muscle
gastrocnaemius muscle
plantaris muscle
popliteal muscle

Question 7

describe the path of the common fibular nerve?

Answer 7

smaller lateral branch of the sciatic nerve
traverses the fossa close to the medial border of the biceps femoris
exits the fossa superficial to the lateral head of the gastrocnaemius
crosses posterior aspect of the head of the fibula
winds around the neck of the fibula before dividing into its terminal branches

Question 8

describe the path of the popliteal artery

Answer 8

enters popliteal fossa by passing under the semimembranous muscle
travels through the fossa inferolaterally
enters the posterior compartment of the leg

Question 9

what does the popliteal artery do?

Answer 9

branches off to form 5 genicular arteries
- superior medial
- superior lateral
- middle
- inferior medial
- inferior lateral
all supply ligaments and capsule of the knee
gives off muscular branches which supply soleus, gastrocnaemius, plantaris and hamstrings

Question 10

what forms the genicular anastomoses and what is its function?

Answer 10

the 5 genicular branches of the popliteal artery
surrounds the knee joint
maintains blood supply to the knee while flexed by bypassing the popliteal artery

Question 11

what is the popliteal vein and where is it?

Answer 11

continuation of the posterior tibial vein

lies superficial to the popliteal artery within the same fibrous sheath

Question 12

describe the path of the popliteal vein

Answer 12

continuation of the posterior tibial vein

exits the fossa superiorly and becomes the femoral vein as it passes through the adductor hiatus

Question 13

what is the pathway of the short saphenous vein?

Answer 13

travels superiorly in the posterior aspect of the leg from the lateral part of the dorsal venous arch
travels within the popliteal fascia before penetrating it and anastomosing with the popliteal vein

Question 14

what are the functions of the posterior muscles of the leg?

Answer 14

plantarflexion
flex the toes
invert the foot
2 can flex the knee

Question 15

what nerve supplies the posterior compartment of the leg?

Answer 15

tibial branch of sciatic

Question 16

what are the muscles of the superior posterior compartment?

Answer 16

gastrocnaemius
plantaris (small, thin)
soleus

Question 17

where does the gastrocnaemius originate and insert?

Answer 17

medial and lateral heads originate on the medial and lateral heads of the femur
insert at the calcaneous (via achilles)

Question 18

what are the functions of the gastrocnaemius?

Answer 18

plantarflexion and flexion of the knee

Question 19

where does the plantaris originate and insert?

Answer 19

lower part of supracondylar ridge

inserts at calcaneous via achilles

Question 20

what does the planatris do?

Answer 20

plantarflexion

flexion on knee

Question 21

where does the soleus originate and insert?

Answer 21

proximal ends of tibia and fibula

inserts at the calcaneous via achilles

Question 22

what does the soleus do?

Answer 22

plantarflexion

Question 23

what are the 3 deep muscles in posterior compartment?

Answer 23

popliteus

Question 24

where does the popliteus originate and insert?

Answer 24

originates on posterior surface of proximal tibia
inserts on lateral femoral condyle
penerates joint capsule of knee

Question 25

what does the popliteus do?

Answer 25

unlocks the knee by laterally rotating the femur

Question 26

what are the 4 deep muscles of the posterior compartment of the leg?

Answer 26

popliteus
flexor hallicus longus (lateral)
flexor digitorum longus (medial)
tibialis posterior (intermediate)

Question 27

where does the flexor hallicus longus originate and insert?

Answer 27

posterior surface of lower fibula and adjacent interosseous membrane and inserts at base on big toe

Question 28

what does the flexor halicus longus do?

Answer 28

flexes the big toe

Question 29

where does the flexor digitorum longus originate and insert?

Answer 29

originates posterior surface of medial tibia

inserts at bases of distal 4 lateral phalanges

Question 30

what does the flexor digitorum longus do?

Answer 30

flexes the digits

Question 31

where does the tibialis posterior originate and insert?

Answer 31

originates between the tibia and fibula at interosseous membrane
inserts on tuberosity of navicular and medial cuneiform

Question 32

what does the tibialis posterior do?

Answer 32

plantarflexion
inverts the foot
supports medial arch of the foot

Question 33

what/where is the sural nerve?

Answer 33

formed by fusion of branches of tibial and common fibular nerves
sits at posterior leg/ankle above the achilles

Question 34

what is the flexor retinaculum?

Answer 34

thickening of the crural fascia which forms the roof of the tarsal tunnel
extends from medial malleolus to calcaneous

Question 35

what is crural fascia?

Answer 35

deep fascia of the leg

Question 36

where is the posterior tibial artery?

Answer 36

where the popliteal artery bifurcates into the posterior tibial and fibular arteries on the posterior surface of the tibia

Question 37

what are vena comitants?

Answer 37

veins which lie in close proximity to an artery and use its pulsation to propel blood back up through them

Question 38

what is the tarsal tunnel?

Answer 38

space at medial malleolus created by the flexor retinaculum which allows structures to pass through it?

Question 39

which structures pass through the tarsal tunnel?

Tom, Dick a Very Nervous Harry

Answer 39

Tibialis anterior tendon
flexor Digitorum longus tendon
posterior tibial Artery and Veins
tibial Nerve
flexor Hallicus longus tendon