Dorsum of Foot Lab

Question 1

Overlies shafts of the metatarsal bones

Answer 1

dorsal venous arch

Question 2

Medially the dorsal venous arch joins ___ to form ___.

Answer 2

joins Medial dorsal digital vein of the great toe to form the medial marginal vein

Question 3

Anterior to the medial malleolus, the medial marginal vein becomes the ____.

Answer 3

Great Saphenous Vein

NOTE: GSV begins anterior to the medial malleolus**

Question 4

Laterally the dorsal venous arch joins the ___ to form the ___.

Answer 4

Joins Lateral Dorsal digital vein of the 5th toe to form the lateral marginal vein

Question 5

Inferior to the lateral malleolus, the lateral marginal vein becomes ___.

Answer 5

Small saphenous vein

Question 6

Dorsal Metatarsal Veins

Answer 6

• the 4 of them drain into the dorsal venous arch.
• Located in metatarsal spaces
• origin = dorsal digital veins of toes

** No 2 cadavers are alike in their venous distribution

Question 7

Saphenous Nerve

Answer 7

• sensory branch of the femoral nerve
• follows great saphenous vein in leg on lateral side
• anterior to medial malleolus
• skin along medial side of foot innervated by this

Question 8

Sural Nerve

Answer 8

• Inferior to lateral malleolus
• follows to small saphenous vein
• becomes the Lateral Dorsal cutaneous nerve of foot

Question 9

Lateral Dorsal cutaneous Nerve

Answer 9

• from the Sural Nerve on lateral side
• terminal part= 10th Dorsal digital nerve**
• Occasionally can give rise or anastomose with intermediate dorsal cutaneous nerve

Question 10

Superficial Peroneal Nerve terminal branches _____

Answer 10

Intermediate dorsal cutaneous nerve

medial dorsal cutaneous nerve

Question 11

Medial Dorsal cutaneous Nerve

Answer 11

• communicates with saphenous nerve and medial terminal branch of deep peroneal
• gives rise to one dorsal digital nerve (1st Dorsal Digital Nerve) and 1st Common Dorsal Digital Nerve

Question 12

1st Dorsal Digital Nerve

Answer 12

Innervates medial side of great toe

Question 13

1st Common dorsal Digital Nerve

Answer 13

Courses to space between toes 2 and 3, where it divides into the 4th and 5th dorsal digital nerves

Question 14

Intermediate Dorsal Cutaneous Nerve

Answer 14

Divides into 2nd and 3rd Common dorsal Digital nerves for intermetatarsal spaces 3 and 4

Each common divides to give two dorsal digital nerves

Question 15

Deep Peroneal Nerve

Answer 15

• courses into foot from below tendon of Extensor Hallucis Longus
• terminal branches= Lateral and Medial Terminal Branches

Question 16

Lateral Terminal Branch of Deep Peroneal n

Answer 16

disappears below extensor digitorum brevis muscle to supply it with motor innervation**
- also supplies extensor halluces brevis m.

(artery running laterally with nerve is the lateral tarsal branch of dorsalis pedis artery)

Question 17

Medial Terminal Branch of Deep Peroneal n.

Answer 17

• follows dorsalis pedis a. and tendon of extensor hallucis longus to reach 1st intermetatarsal space
• divides into: 2nd and 3rd Dorsal Digital nerves for adjacent sides of toes 1 and 2

Question 18

Can the Intermediate dorsal cutaneous nerve be missing?

Answer 18

Yes!! In this case, the lateral dorsal cutaneous nerve supplies the skin normally innervated by the intermediate.

Question 19

Thickenings of the crural fascia: ____.

Answer 19

Superior and Inferior Extensor Retinacula are thickenings of the deep fascia (crural fascia)

Question 20

Superior Extensor Retinaculum

Answer 20

• Lies superior to level of malleoli and courses between tibia and fibula

Tendons passing below the retinaculum: Extensor Digitorum Longus, Extensor Hallucis Longus, Peroneus tertius, Tibialis anterior

Question 21

Inferior Extensor Retinaculum

Answer 21

• Usually “Y” shaped band
  Stem: Frondiform Ligament- attached to lateral surface of calcaneus (sinus tarsi and sinus canal)

  Limbs (course medially): 
             Superomedial Limb- attaches medial malleolus
             Inferomedial Limb- blends with deep fascia at cuneonavicular joint

-Note: Can be cruciate “X” shaped
25% of time there is Superolateral Limb
Extends to lateral malleolus

Question 22

Synovial Sheaths

Answer 22

• look for sheaths under the inferior extensor retinaculum
• surround tendons of the extensor muscles
• 3 sheaths, one for each tendon:
  
  1. Tibialis Anterior
  2. Extensor Hallucis Longus
  3. Common sheath to Peroneus Tertius and Extensor Digitorum Longus

Question 23

Tendons confined by:

Answer 23

Deep fibers of the superior extensor retinaculum serve to compartmentalize and confine the tendons

Question 24

Extensor Digitorum Brevis

Answer 24

• tendons to medial 4 toes
• medial or 1st tendon can have separate belly called Extensor Hallucis Brevis
• rest of muscle )Extensor Digitorum Brevis to toes 2, 3, 4
• Note: tendons join the lateral side of tendons of extensor halluces longus and extensor digitorum longus

Question 25

Dorsalis Pedis a.

Answer 25

Distal continuation of anterior tibial artery at ankle joint

Question 26

First and largest Branch of Dorsalis Pedis artery

Answer 26

Lateral Tarsal Artery - arises near distal border of inferior extensor retinaculum - courses inferolaterally deep to extensor digitorum brevis m. along with lateral terminal branch of deep peroneal n. (may be a 2nd Lateral Tarsal a.) - communicating branches with perforating branch of peroneal artery (branch of posterior tibial artery)

Question 27

Arise from medial side of Dorsalis Pedis a.

Answer 27

1-2 medial tarsal arteries - usually pretty small - connection with medial malleolar rete (plexus of arteries superficial to medial malleolar)

Question 28

Arcuate Artery

Answer 28

- branch of Dorsalis Pedis | - arises near base of 2nd metatarsal and courses laterally, deep to extensor digitorum longus and brevis

Question 29

Arise directly from Arcuate Artery

Answer 29

2nd, 3rd, 4th dorsal metatarsal arteries

Question 30

Dorsal metatarsal arteries

Answer 30

- course across anterior surface of dorsal interossei muscles to supply them - each artery gives rise to 2 dorsal digital arteries

Question 31

Dorsal Digital arteries

Answer 31

Break up into numerous branches and anastomose with proper plantar arteries

Question 32

Proximal (posterior) perforating Branches

Answer 32

- originate from plantar arch | - perforate dorsally to join proximal ends of dorsal metatarsal arteries

Question 33

Distal (anterior) perforating Branches

Answer 33

- branches of plantar metatarsal arteries | - received by the dorsal metatarsal arteries

Question 34

Dorsal metatarsal arteries receive the Distal perforating branches and become:

Answer 34

Common Dorsal Digital arteries Each common then divides at webbing of toes to form 2 dorsal digital arteries

Question 35

Dorsal Digital Arteries

Answer 35

1-10 1st Dorsal Digital is a branch from the 1st Dorsal Metatarsal a. (terminal branch of dorsalis pedis a. )

Question 36

Terminal Branches of Dorsalis Pedis a.

Answer 36

1st Dorsal Metatarsal a. | Deep Plantar a.

Question 37

1st Dorsal Metatarsal a.

Answer 37

- gives off 1st dorsal digital artery--> to medial side of 1st toe - does not receive a proximal perforating branch - does receive a distal perforating branch---> then known as 1st Common Dorsal Digital a.

Question 38

Anastomoses with terminal part of arcuate artery and perforating branch of peroneal artery:

Answer 38

Lateral Tarsal Artery

Question 39

1st Common Dorsal Digital a. gives rise to:

Answer 39

2nd and 3rd dorsal digital arteries

Question 40

2nd Common Dorsal Digital a. gives rise to:

Answer 40

4th and 5th dorsal digital arteries

Question 41

3rd Common Dorsal Digital a. gives rise to:

Answer 41

6th and 7th dorsal digital arteries

Question 42

4th Common dorsal Digital a. gives rise to:

Answer 42

8th and 9th dorsal digital arteries

Question 43

Number of Proximal Perforating branches

Answer 43

3

Question 44

Number of Distal perforating Branches

Answer 44

4

Question 45

Perforating branch of peroneal a.

Answer 45

Pierces through interosseous membrane to gain access to dorsal part of foot. - usually small but can be large on occasion and take over vascular supply of dorsal foot.