topic 19

Question 1

dorsum of the foot muscles-intrinsic

Answer 1

Extensor Digitorum Brevis

Origin: Superolateral surface of the calcaneus.
Insertion: Bases of the proximal phalanges of the 2nd, 3rd, and 4th toes.
Function: Extends the 2nd to 4th toes.
Innervation: Deep fibular (peroneal) nerve.
Extensor Hallucis Brevis

Origin: Superolateral surface of the calcaneus.
Insertion: Base of the proximal phalanx of the big toe.
Function: Extends the big toe.
Innervation: Deep fibular (peroneal) nerve.

Question 2

extrinsic

Answer 2

Tibialis Anterior
Origin: Lateral condyle and upper two-thirds of the lateral surface of the tibia.
Insertion: Medial cuneiform and base of the first metatarsal.
Function: Dorsiflexes and inverts the foot.
Innervation: Deep fibular (peroneal) nerve.

Extensor Digitorum Longus
Origin: Lateral condyle of the tibia, upper three-fourths of the anterior fibular shaft, and interosseous membrane.
Insertion: Middle and distal phalanges of the 2nd to 5th toes.
Function: Extends the toes and dorsiflexes the foot.
Innervation: Deep fibular (peroneal) nerve.

Extensor Hallucis Longus
Origin: Middle portion of the anterior surface of the fibula and interosseous membrane.
Insertion: Distal phalanx of the big toe.
Function: Extends the big toe and dorsiflexes the foot.
Innervation: Deep fibular (peroneal) nerve.

Fibularis (Peroneus) Tertius
Origin: Distal third of the anterior surface of the fibula and interosseous membrane.
Insertion: Dorsum of the base of the 5th metatarsal.
Function: Dorsiflexes and everts the foot.
Innervation: Deep fibular (peroneal) nerve.

Question 3

fasciae + tendons n’ tendon sheaths

Answer 3

Dorsal Fascia: This is the superficial fascia covering the dorsum of the foot, continuous with the fascia of the leg and plantar fascia.

Extensor Retinacula: Strong fibrous bands that hold the extensor tendons in place.

Superior Extensor Retinaculum: Located just above the ankle joint.
Inferior
Extensor Retinaculum: Y-shaped band located over the dorsum of the foot, securing the tendons as they pass into the foot.

The tendons of the extrinsic muscles (tibialis anterior, extensor digitorum longus, extensor hallucis longus, and fibularis tertius) are held in place by the extensor retinacula and pass through synovial sheaths to reduce friction and facilitate smooth movement.

Question 4

vessels

Answer 4

Arteries
Dorsalis Pedis Artery
Continuation of the anterior tibial artery.
Runs along the dorsum of the foot towards the first intermetatarsal space.
Branches: Lateral tarsal artery, arcuate artery, deep plantar artery, and first dorsal metatarsal artery.
Supplies: Dorsum of the foot, toes, and some intrinsic muscles.

Veins
Dorsal Venous Arch: medial marginla vein continues GSV while lateral marginal vein continue as SSV

Question 5

nerves

Answer 5

Nerves
Superficial Fibular (Peroneal) Nerve
Supplies: Skin of most of the dorsum of the foot (except the web space between the first and second toes).
Sensory Branches: Dorsal digital nerves.
Deep Fibular (Peroneal) Nerve
Supplies: Intrinsic muscles on the dorsum of the foot (extensor digitorum brevis and extensor hallucis brevis) and the skin of the web space between the first and second toes.
Sural Nerve
Supplies: Skin of the lateral aspect of the foot.
Saphenous Nerve
Supplies: Skin of the medial side of the foot up to the first metatarsophalangeal joint.