Ch. 23: Popliteal Fossa and Vessles/Nerves

Question 1

Boundaries of popliteal fossa

Answer 1

Superolateral: tendon of biceps femoris

Superomedial: semimembranous (mostly) and semitendinosus

Inforlateral: lateral head of gastrocnimeus

IM: medial head of gastrocnemius

Roof: popliteal fascia of fascia lata

Floor: posterior surface of capsule of knee and popliteus muscle

Question 2

What does the popliteal fossa contain?

Answer 2

1. termination of posterior femoral cutaneous nerve
2. division of sciatic n. into tibial and common fibular components
3. muscular cutaneous branches of tibial n.
4. cutaneous branches of common fibular n.
5. popliteal v. and its tributaries
6. popliteal artery and its branches
7. popliteal lymph nodes, lymphatic vessels and fat

Question 3

Popliteal a.

Answer 3

• direct continuation of femoral a. after it emerges from adductor hiatus. It terminates at inferior border of popliteus by dividing into anterior and posterior tibial aa.

Branches:

• lat/med. superior genicular aa.
• lat/med. inferior genicular aa.
• sural branches (2)
• anterior tibial a.
• posterior tibial a.

Question 4

Lat/Medial superior genicular aa.

Answer 4

located deep to hamstring musculature; pass SUPERFICIALto heads of gastrocnemius

Question 5

Lat/Med. inferior genicular aa.

Answer 5

located DEEP to heads of gastrocnemius; pass on or near superior surface of popliteus muscle

Question 6

Middle Genicular a.

Answer 6

• arises from anterior surface of popliteal a. ; passes through the capsule of knee to supply the interior of the knee joint

Question 7

sural branches of popliteal a.

Answer 7

• pass directly into lateral and medial heads of gastrocnemius muscle

Question 8

Anterior Tibial a.

Answer 8

• posteriorally: gives off posterior tibial recurrent a. and circumflex fibular a. that both join the genicular anastamoses
• Anteriorally: gives off anterior tibial recurrrent a. (which goes to genicular anastomoses) and medial/lateral malleolar branches. (which go to malleoli deep to tendons in ankle - malleolar network)
• terminates in dorsalis pedis a. which courses along the medial dorsum of foot

Question 9

Dorsalis Pedis a.

Answer 9

• terminal branch of anterior tibial a. as it passes inferior to superior extensor retinaculum
• gives off lateral and medial tarsal aa., arcuate a. first dorsal metatarsal a. and deep plantar a.

NOTE: each dorsal metatarsal artery communicates with plantar circulation via perforating a.

Question 10

Posterior tibial a.

Answer 10

• gives off circumflex fib.
• fibular a. which runs laterally and anastomses in the plantar portion of the foot with the deep plantar a.
• the fibular a. has lateral calcaneal and posterior/lateral malleolar branches - both which anastamose with branches of the ant. tibial a.
• communicating branch connects the posterior tibial a. and the fibular a.
• medial and lateral plantar arteries = terminal branches of posterior tibial a.

(see the drawing!@!! draw this out? )

Question 11

Genicular anastomosis: where do vessels come from?

Answer 11

• provides a rich supply to the capsule of the knee joint as well as surrounding musculature. It is composed of ten vessles which arise from

1. lateral femoral circumflex a.
2. femoral a.
3. popliteal a.
4. anterior tibial a.
5. posterior tibial a.

Question 12

what does the sciatic n. branch into?

Answer 12

descends withing popliteal fossa. upon exiting it bifurcates into tibial n. and common fibular n.

Question 13

Common fibular n. : where is it in popliteal fossa? what does it provide in popliteal fossa? What muscel does it follow? What muscle does it pierve inferior to the head of the fibula and what does it turn into?

Answer 13

L4,5- S1,2

• courses superficially and laterally (hugs the medial surface of biceps femoris muscle) within the popliteal fossa
• provides the lateral sural cutaneous n. to posterior leg while in popliteal fossa
• as it leaves popliteal fossa, it continues to follow the course of the biceps femoris tendon to the head of the fibula
• the common fibular nerve pierces the fibularis longus muscle inferior to the head of fibular where it divides into the superficial and deep fibular nerves.

Question 14

Superficial Fibular n: where does it go? where does it provide muscular branches to along the way? what does it bifurcate into in the lower leg?

Answer 14

L5-S1,2,

• descends along the fibula betwen teh muscles of the lateral and anterior compartments
• provides muscular branches to fibularis longus and brevis
• becomes superficial in distal third of leg to innervate the anterior distal third of leg and divide into medial dorsal cutaneous nerves and intermediate dorsal cutaneous nerves which provide dorsal digital branches to all the toes

Question 15

Deep Fibular n. : where does it go? what compartment does it innervate all muscles to? where does it go in foot, and what does it split into and innervate?

Answer 15

L4,5

• branches from common fibular n. within the fibularis longus muscle
• passes into anterior compartment by piercing extensor digitorum muscle
• descneds through anterior compartment lateral to anterior tibial a. and veins

**- innervates all muscles to anterior compartment **

• passes DEEP to extensor retinacula and divides into lateral andmedial terminal branches
• Lateral branch: passes deep to extensor digitorum brevis and gives sensory fibers to joints in foot
• Medial branch: follows first dorsalmetatarsal a. and cutaneous innervates web between first and second toe

Question 16

Tibial n.: where does it go? what does it give off in popliteal fossa? where does it exit popliteal fossa? What does it innervate all of???

Answer 16

L4,5 - S1,2,3

• located superficially and centrally within popliteal fossa

whilte in popliteal fossa gives branches to gastroc and plantaris mscles (sural branches) as well as cutaneous **medial sural cutaneous n. **

• leaves popliteal fossa deep to gastrocnemius muscle
• at superior edge of soleus provides musclar branches to popliteus and soleus passing deep
• descends b/w the superficial and deep posterior muscular compartments in company with posterior tibial a. and veins

- innervates ALL posterior leg musculature

• under flexor retinaculum passes between dick and harry (fledor digitorum and hallucis longus)