Lecture 13: Lower Extremity part 3

Question 1

1) What are the origins of the genicular periarticular arterial anastomosis of the knee region?
2) What the 5 typical components of this anastomosis? (said we don’t need to know)
3) What do they allow for?

Answer 1

1) Various origins (some above, some inferior, etc)
2) Superior lateral & medial geniculate aa.
-middle geniculate a.
-inferior lateral a. & medial geniculate aa.
2) Allows for blood supply to leg during full range of motion; flexion and extension

Question 2

What are the veins of the popliteal fossa? Where are they?

Answer 2

1) Popliteal vein: deep to investing fascia
-Other veins following smaller arteries
2) Small saphenous v: within superficial fascia

Question 3

1) Where does posterior tibial vein turn into the popliteal vein?
2) Where does the popliteal vein turn into the femoral vein?

Answer 3

1) Inferior margin of popliteus
2) Adductor hiatus

Question 4

Sciatic nerve divides into what (proximally or distally)?

Answer 4

Common fibular and tibial nerves

Question 5

1) What does the tibial nerve supply motor to?
2) What nerve innervates the skin of the posterolateral leg and foot?
3) What two nerves come together to form the nerve from #2?

Answer 5

1) Posterior compartment of the leg (plantar flexor of the ankle/foot, flex the knee)
2) Sural nerve
3) Medial sural cutaneous nerve + sural communicating branch of the common fibular nerve

Question 6

Only cutaneous nerve of the leg that comes from the femoral n is the _____________ nerve , the rest comes from the ___________ nerve.

Answer 6

saphenous; sciatic

Question 7

What 2 things does the common fibular (peroneal) nerve divide into? What do these supply and what do they branch into?

Answer 7

1) Deep fibular (peroneal) n. for the anterior compartment of the leg (dorsi flexors of the ankle/foot)
-Media sural and sural n. to posterior leg and lateral foot
2) Superficial fibular (peroneal) n. for the lateral compartment (evertors of the foot)
-Lateral sural nerve to leg and dorsum of foot

Question 8

What bone of the crura (leg) is weight bearing?

Answer 8

1) Tibia: weight bearing
2) Fibula: minimal if any weight bearing

Question 9

List the 3 main compartments of the leg (crura) and what action each is responsible for. List 2 subcompartments as well.

Answer 9

1) Anterior: dorsiflexors ankle/foot and toes (incl extensors of toes)
2) Lateral: evertors of foot
3) Posterior: plantar flexion of ankle and toes & invertors of ankle/foot
-Deep & Superficial compartment

Question 10

1) What are the compartments of the lower leg divided by? (2 things)
2) What divides the posterior compartment?

Answer 10

1) Anterior and posterior intermuscular septum and interosseous membrane
2) Transverse intermuscular septum

Question 11

1) What are the muscles of the anterior compartment of the lower leg?
2) What type of movements do these do?
3) What nerve and artery supply here?

Answer 11

1) EDL, EHL, TA
-aka extensor digitorum longus, extensor hallucis longus, and tibialis anterior
2) Dorsiflexor ankle & extensors of toes, some inversion
3) Deep fibular n. and anterior tibial a.

Question 12

What are the dorsiflexors of the ankle and what does each do?

What compartment do they come from?

Answer 12

Anterior compartment:
1) Tibialis anterior TA: some inversion of foot
2) Fibularis tertius FT: some eversion of foot based on lateral insertion

Question 13

What are the two extensors of the toes?

Answer 13

1) Extensor digitorum longus (EDL)
2) Extensor hallucis longus (EHL)

Question 14

What are the 2 muscles of the lateral compartment of the lower leg?

Answer 14

FL and FB
(aka fibularis tertius and fibularis brevis)

Question 15

What are retinacula? What do they do?

Answer 15

2 thickenings of investing fascia (near ankle on anterior side), keep tendons flush to the body

Question 16

What nerve is located near the head of the fibula?

Answer 16

Common fibular (peroneal) nerve

Question 17

Medial to the tibialis anterior tendon are what two tendons?

Answer 17

1) Extensor hallucis longus
2) Extensor digitorum longus

Question 18

Regarding the evertors of foot, what compartment are they in and where do the tendons pass?
What are these two tendons and where do they insert?

Answer 18

Lateral; tendons pass posterior to lateral malleolus
1) Fibularis (peroneus) longus: inserts plantar surface of 1st tarsometatarsal region
2) Fibularis (peroneus) brevis: inserts base of 5th MT

Question 19

1) What nerve innervates the lateral compartment of lower leg?
2) What does this branch into? What does this innervate?

Answer 19

1) Superficial fibular (peroneal) nerve
2) Lateral sural nerve; to lateral surface of leg and dorsum of foot

Question 20

1) What artery supplies the lateral compartment of lower leg?
2) Where are the veins here?

Answer 20

1) No dedicated artery; perforating branches of anterior tibial and fibular aa.
2) Veins accompany [arteries]

Question 21

1) Which tendon runs from the medial side anterior side of foot to the lateral more posterior side?
2) What other tendon is near here?

Answer 21

1) Fibularis longus
2) Tibialis posterior tendon (goes posterior to malleolus medially)

Question 22

To recap:
1) Anterior compartment of lower leg contains muscles that do what actions?
2) What nerve supplies this compartment?
3) What artery?

Answer 22

1) Dorsiflexors of ankle/foot, extensors of toes
2) Deep fibular nerve
3) Anterior tibial artery

Question 23

To recap, lateral compartment of lower leg:
1) Contains muscles that does what action?
2) What nerve supplies this compartment?
3) What 2 arteries?

Answer 23

1) Evertors of the foot
2) Superficial fibular nerve
3) Perforating branches of anterior tibial artery proximally, and fibular artery distally

Question 24

1) What movements are the posterior compartment of the lower leg responsible for?
2) Calf muscles in superficial post. compartment are called what?
3) What are the muscles in this superficial post. group?
4) What other group of muscles are in the posterior compartment?

Answer 24

1) Plantar flexion of ankle, foot, toes
2) Triceps Surae
3) Soleus and M/L Gastrocnemius; plantaris mm.
4) Deep (FHL, FDL)

Question 25

What are the 4 deep muscles of the posterior compartment?

Answer 25

1&2) FHL, FDL mm.
3&4) TA also stabilizes and inverts foot, along with TP (deep posterior compartment)

Question 26

1) What supply both the Triceps Surae and the deep muscles of the posterior compartment?
2) Where are they?

Answer 26

1) Posterior tibial and fibular vessels
2) Deep posterior compartment

Question 27

1) How many heads does the gastrocnemius “calf” muscle have? How many joints does it act on?
2) List the 3 movements this muscle is responsible for

Answer 27

1) Two heads & two joints
2) Plantar flexion at ankle/foot, raises heel (walking), & flexion at knee

Question 28

1) What muscle is in the “deep calf”?
2) What muscle is it deep to?
3) Does it cross the knee or act on it?
4) What movement is it responsible for?

Answer 28

1) Soleus
2) Gastrocnemius mm.
3) Does not cross knee; no action at knee
4) Plantar flexion at ankle/foot

Question 29

1) Where does the soleus muscle originate?
2) Where does the popliteal artery travel? Where does it bifurcate, and what does it divide into?
3) What 2 muscles does the plantaris muscle tendon run between?

Answer 29

1) Tendinous Arch (hiatus for vessels and nerve) @ inferior popliteal fossa
2) Bifurcates as is travels inferior from popliteal fossa into terminal branches (anterior/posterior tibial arteries)
3) Soleus and gastroc mm.