Gross Anatomy- Dorsum of Foot

Question 1

Name the two Extensor mm of the Dorsum of the Foot

Answer 1

Extensor Digitorum Brevis

Extensor Hallucis Brevis

Question 2

Describe the location and characteristics of the Extensor Digitorum Brevis m of the Dorsum of the foot.

Answer 2

• On dorsum of foot
• Has 3 tendons

• O: Calcaneus; interosseous talocalcaneal l.; stem of inferior extensor retinaculum

• *I:** Long extensor tendons of 3medial digits (toes 2-4)
• *A:** Aids EDL in extension of 3 medial digits at the MP and IP joints
• *N**: Lateral branch deep fibular n. (L5 or S1 or both)
• *B**: Lateral tarsal a.

Question 3

Explain the location and characteristics of the Extensor Hallucis Brevis m

Answer 3

• On dorsum of foot

• *• O:** Calcaneus; interosseous talocalcaneal l.; stem of inferior extensor retinaculum
• *I:** Dorsal aspect base of proximal phalanx of 1st digit
• *A:** Aids EHL in extension of 1st digit at the MP joint
• *N:** Lateral branch of deep fibular n. (L5 or S1 or both)
• *B:** Lateral tarsal a.

Question 4

Vasculature of Dorsum of Foot- Name the Arteries

Answer 4

Dorsalis pedis a

Lateral tarsal a

Arcuate a

2nd 3rd and 4th dorsal metatarsal aa

dorsal ditgital aa

1st dorsal metatarsal a

Deep plantar a

Question 5

Describe the Dorsal Pedis a

Answer 5

direct continuation of anterior tibial a.
 Begins midway between malleoli
 One of the four places to take a pulse

Question 6

Describe the Lateral Tarsal a

Answer 6

• Runs beneath extensor digitorum brevis m.
• Anastomoses with arcuate a.

Question 7

Describe the Arcuate a

Answer 7

• Runs laterally, deep to extensor tendons
• Gives rise to 2nd, 3rd, and 4th dorsal metatarsal aa.
o Connected to deep plantar arch and plantar metatarsal aa. via perforating branches
o Divide into dorsal digital aa.

 Terminates as into:

• 1st dorsal metatarsal a.
o Supplies both sides of great toe
• Deep plantar a.
o Dives deep to help form deep plantar arch

Question 8

Describe the Vein of the Dorsum of the foot

Answer 8

o Dorsal venous arch –

 Gives rise to great and small saphenous vv.
 Drains most of foot via digital and communicating veins from sole

Question 9

Describe the significance of the Palpation of Dorsalis Pedis Pulse

Answer 9

• Evaluated during examination of peripheral vascular system
• Easy to palpate as they are subcutaneous
o Located just lateral to EHL t.
o Done with feet slightly dorsiflexed
• Diminished or absent dorsalis pedis pulse usually suggests vascular insufficiency resulting from arterial disease
• Congenitally non-palpable dorsalis pedis pulses are possible
o Variation is usually bilateral
o Would be replaced by enlarged perforating fibular a.