Anatomy of the Leg and Foot Muscles

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Questions and Answers

What is the primary action of the fibularis brevis muscle?

Dorsiflexion of the foot

Inversion of the foot

Flexion of the foot

Eversion of the foot (correct)

Which nerve supplies the fibular muscles?

Deep fibular nerve

Common fibular nerve (correct)

Tibial nerve

Sural nerve

What is the primary function of the anterior tibial artery in the leg?

It supplies blood to the anterior compartment and foot. (correct)

It provides circulation to the muscles of the lateral compartment.

It supplies blood to the posterior compartment of the leg.

It primarily circulates blood in the knee joint.

What is the role of the ankle retinacula?

To maintain the position of structures from the leg to the foot Signup and view all the answers

Which nerve innervates all muscles in the anterior compartment of the leg?

Deep fibular nerve Signup and view all the answers

Where does the superior extensor retinaculum attach?

To the anterior borders of the fibula and tibia Signup and view all the answers

What anatomical structure does the deep fibular nerve pass underneath in the leg?

Extensor digitorum longus Signup and view all the answers

Which structure is NOT supplied by the superficial fibular nerve?

Web space between the great and second toes Signup and view all the answers

Which is NOT a branch of the anterior tibial artery?

Superficial fibular branch Signup and view all the answers

What shape is the inferior extensor retinaculum?

Y-shaped Signup and view all the answers

What action is primarily facilitated by the fibularis longus muscle?

Eversion and plantar flexion of the foot Signup and view all the answers

Which of the following structures is located deep to the extensor retinacula, from lateral to medial?

Dorsalis pedis artery Signup and view all the answers

The deep fibular nerve contributes to the innervation of which muscles on the dorsal aspect of the foot?

Extensor digitorum brevis and dorsal interossei Signup and view all the answers

What is the origin of the fibularis brevis muscle?

Lower two-thirds of the lateral surface of the fibula Signup and view all the answers

Which artery primarily supplies the lateral compartment of the leg?

Fibular artery via perforating branches Signup and view all the answers

Where does the dorsalis pedis artery continue after leaving the leg?

On the dorsal aspect of the foot Signup and view all the answers

Which muscle is primarily responsible for dorsiflexion of the foot at the ankle joint?

Tibialis anterior Signup and view all the answers

What is the primary nerve that innervates the muscles in the anterior compartment of the leg?

Deep fibular nerve Signup and view all the answers

Which compartments does the interosseous membrane not separate in the leg?

Lateral and posterior Signup and view all the answers

Which blood vessel supplies the anterior compartment of the leg?

Anterior tibial artery Signup and view all the answers

Which of the following muscles is NOT considered an ankle dorsiflexor?

Fibularis longus Signup and view all the answers

The function of the muscles in the posterior compartment of the leg is primarily to perform what action?

Plantarflexion of the ankle Signup and view all the answers

What action is performed by the extensor digitorum longus muscle?

Extension of the toes Signup and view all the answers

Which structure divides the leg into anterior, posterior, and lateral compartments?

Intermuscular septa Signup and view all the answers

What is the origination point of the anterior tibial artery?

Popliteal artery Signup and view all the answers

Which muscle acts as an inverter of the foot?

Tibialis anterior Signup and view all the answers

Study Notes

Leg Anatomy

The leg extends from the knee to the ankle.
The leg's bony structure consists of the tibia (medially) and fibula (laterally). These run parallel.

Leg Compartments

The leg is divided into three compartments: anterior (extensor), posterior (flexor), and lateral (fibular).
These compartments are separated by interosseous membrane and intermuscular septa.
The deep fascia attaches to the tibia's anterior and medial borders.

Anterior Compartment

Muscles: Ankle dorsiflexors (extensors).
Blood Vessels: Anterior tibial vessels.
Nerves: Deep fibular nerve.
Specific muscles include Tibialis Anterior, Extensor Hallucis Longus, Extensor Digitorum Longus, and Fibularis Tertius.

Muscles

Four muscles dorsiflex the foot, extend the toes, and invert the foot; all are innervated by the deep fibular nerve.
The muscles are Tibialis anterior, Extensor hallucis longus, Extensor digitorum longus, and Fibularis tertius.
Details about origin, insertion, nerve supply, and action are provided in the tables for tibialis anterior, extensor digitorum longus, extensor hallucis longus, and fibularis tertius.

Anterior Tibial Artery

Originates in the posterior compartment of the leg.
Travels through the interosseous membrane into the anterior compartment.
Lies between the tibialis anterior and extensor hallucis longus tendons.
Emerges from the leg, passing anterior to the ankle joint, and continues as the dorsalis pedis artery in the foot.
Branches include recurrent branches around the knee joint, muscular branches, anterior medial malleolar artery, anterior lateral malleolar artery and dorsalis pedis artery.

Deep Fibular Nerve

Originates in the lateral compartment, branching from the common fibular nerve.
Passes deep to the extensor digitorum longus.
Reaches the anterior interosseous membrane and descends with the anterior tibial artery.
Innervates all muscles in the anterior compartment.
Enters the dorsal aspect of the foot, innervating the extensor digitorum brevis.
Contributes to the innervation of the first two dorsal interossei muscles.
Supplies skin between the great and second toes.

Lateral Compartment

Muscles: Two evertors of the ankle joint (Fibularis longus and Fibularis brevis).
Blood Vessels: Perforating branches of the fibular artery.
Nerves: Superficial fibular nerve.

Superficial Fibular Nerve

Originates from the common fibular nerve.
Supplies the fibularis muscles.
Penetrates the deep fascia in the lower leg and enters the foot.
Divides into medial and lateral branches.
Supplies most dorsal areas of the foot and all toes, except: the web space between the great and second toes (supplied by deep fibular nerve) and the lateral side of the little toe (supplied by the sural branch of tibial nerve).

Ankle Retinacula

Thickening of deep fascia on the lower leg.
Five retinacula: two extensor retinacula (upper and lower), two fibular retinacula (upper and lower), and one flexor retinaculum.
Maintain structures passing from the leg into the foot, preventing displacement.

Extensor Retinacula

Superior extensor retinaculum: thickens distal leg deep fascia, superior to the ankle joint, attaches to anterior borders of fibula and tibia.
Inferior extensor retinaculum: Y-shaped, attaches to lateral calcaneus, crosses foot medially to medial malleolus, and wraps around the foot medially to plantar aponeurosis.

Structures Deep to Extensor Retinacula

From lateral to medial: tendon of fibularis tertius, tendon of extensor digitorum longus, dorsalis pedis artery, tendon of extensor hallucis longus, tendon of tibialis anterior.

Fibular Retinacula

Superior fibular retinaculum: extends between the lateral malleolus and the calcaneus.
Inferior fibular retinaculum: attaches to lateral surface calcaneus, blends with inferior extensor retinaculum.
Fibular trochlea has septa separating compartments for fibularis brevis and longus.

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Description

Test your knowledge on the anatomy of the leg and foot, focusing on muscles, nerves, and arteries. This quiz covers key structures such as the fibularis muscles, retinacula, and the anterior tibial artery. Perfect for students of anatomy and healthcare professionals.