Muscle Anatomy: Tibialis & Extensors Quiz

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Questions and Answers

What is the primary action of the Extensor digitorum?

Flex toes

Extend toes (correct)

Rotate toes

Adduct toes

To which structure do the tendons of the Extensor digits longus pass?

Medial four toes

Big toe only

All five toes

Lateral four toes (correct)

Where does the Extensor digitorum originate?

Tip of the tibia

Superior surface of the fibula

Lateral malleolus

Anterior part of the upper surface of the Calcaneum (correct)

What is the insertion point of the Extensor digitalis and its brevis?

Four tendons into the proximal phalanx of the second, third, and fourth toes Signup and view all the answers

Which peripheral nerves are primarily involved with the Extensor digitorum?

Peroneal nerve Signup and view all the answers

What action does the Peroneus Tertius muscle perform?

Everts foot at subtalar and transverse tarsal joints Signup and view all the answers

Which structure is a thickening of deep fascia that maintains the position of tendons around the ankle joint?

Superior Extensor retinaculum Signup and view all the answers

Which nerve supplies the Extensor Digitorum Longus muscle?

Deep peroneal nerve Signup and view all the answers

From which surface does the Tibialis Anterior muscle originate?

Anteromedial surface of the tibia Signup and view all the answers

What is the primary action of the Peroneus Longus muscle?

Everts the foot and plantar flexes at the ankle joint Signup and view all the answers

Which toes are associated with the tendons mentioned in the content?

2nd, 3rd, and 4th toes Signup and view all the answers

What is the role of the Extensor digitorum brevis in relation to the tendons?

It joins on the lateral side of certain tendon. Signup and view all the answers

Where does the tendon join the Extensor digitorum brevis?

On the lateral side of the specified tendons Signup and view all the answers

Which statement correctly describes the relationship between the tendons mentioned?

They are shared by the Extensor digitorum brevis. Signup and view all the answers

What anatomical feature do the mentioned tendons have in common?

They connect with a common tendon. Signup and view all the answers

Why is the location of the tendon on the lateral side significant?

It aids in the lateral movement of the 2nd, 3rd, and 4th toes. Signup and view all the answers

Which is a possible consequence of disruption in the tendons to the 2nd, 3rd, and 4th toes?

Decreased ability to extend those particular toes. Signup and view all the answers

What structure receives the insertion of the Interossei and Lumbrical muscles?

Extensor Expansion Signup and view all the answers

Which muscles insert into the Extensor Expansion?

Interossei Signup and view all the answers

Where are the Interossei and Lumbrical muscles inserted?

Extensor Expansion Signup and view all the answers

What are the lateral parts that are inserted into the structure mentioned in the content?

Two Lateral parts Signup and view all the answers

What is the primary function of the Lumbrical muscles?

Flexion at the metacarpophalangeal joints and extension at the interphalangeal joints Signup and view all the answers

Which muscles are primarily responsible for finger abduction and adduction?

Interossei Signup and view all the answers

What does the term 'Distal ph.' refer to in this context?

Distal phalanx Signup and view all the answers

Study Notes

Tibialis Anterior & Extensor Digitorum Longus

Origin (Tibialis Anterior): Lateral surface of the tibia and interosseous membrane
Insertion (Tibialis Anterior): Medial cuneiform and base of the 1st metatarsal
Action (Tibialis Anterior): Extends foot at the ankle joint and inverts foot at the subtalar and transverse tarsal
Origin (Extensor Digitorum Longus): Anterior surface of the fibula
Insertion (Extensor Digitorum Longus): Extensor expansion of the lateral four toes
Action (Extensor Digitorum Longus): Extends toes and dorsi flexes the foot at the ankle joint

Peroneus Tertius & Extensor Hallucis Longus

Origin (Peroneus Tertius): Anterior surface of the fibula's shaft
Insertion (Peroneus Tertius): Base of the 5th metatarsal bone
Action (Peroneus Tertius): Dorsi flexes the foot at the ankle joint, everts at subtalar and transverse tarsal joints
Origin (Extensor Hallucis Longus): Anterior surface of the fibula's shaft
Insertion (Extensor Hallucis Longus): Base of the distal phalanx of the great toe
Action (Extensor Hallucis Longus): Extends the big toe, dorsi flexes the foot at ankle joint, inverts at subtalar and transverse tarsal joints

Extensor Retinacula

Function: Thickening of deep fascia; keeps tendons in position around the ankle joint
Superior Extensor Retinaculum: Attached to the anterior borders of tibia and fibula, above the ankle
Inferior Extensor Retinaculum: Y-shaped band inferior to the ankle

Structures Passing Deep to Extensor Retinacula

Medial to Lateral: Tibialis anterior, extensor hallucis longus, vessels, nerve (dorsalis pedis), deep peroneal nerve, extensor digitorum longus (Mnemonic: TOM HAVEN NICE DOG)

Lateral Compartment of Leg

Muscles: Peroneus longus, Peroneus brevis
Nerve: Superficial peroneal
Blood Supply: Peroneal artery
Action: Plantar flexion and eversion

Peroneus Longus

Origin: Lateral surface of the fibula's shaft
Insertion: Base of the 1st metatarsal and medial cuneiform
Action: Plantar flexes and everts foot at the ankle, subtalar, and transverse tarsal joints

Peroneus Brevis

Origin: Lateral surface of the fibula's shaft
Insertion: Base of the 5th metatarsal
Action: Plantar flexes and everts the foot at the ankle, subtalar, and transverse tarsal joint

Dorsum of Foot

Muscle: Extensor digitorum brevis
Blood Vessel: Dorsalis pedis
Nerve: Deep & Superficial peroneal
Structure: Extensor muscles, retinacula, and nerves pass across the dorsum; tendons extend to the toes

Extensor Digitorum Brevis

Origin: Upper anterior part of the calcaneus and inferior extensor retinaculum
Insertion: Proximal phalanges of the toes 2-5
Action: Extends the toes 2-5

Insertion of Long Extensor Tendons (Extensor Expansion)

Tendons: Extensor digitorum longus pass to lateral four toes, joined by Extensor digitorum brevis tendons
Fascial Expansion: Forms a fascial expansion on the dorsum of each toe; divides into 3 parts
Central Part: Inserts into base of middle phalanx
Lateral Parts: Inserts into base of distal phalanges
Insertion of Structures: Receives insertion from interossei & lumbrical muscles

Synovial Sheaths of Extensor Tendons on the Dorsum of Foot

Tibialis Anterior: Has its own synovial sheath
Extensor Hallucis Longus: Has its own synovial sheath
Extensor Digitorum Longus & Peroneus Tertius: Share a common sheath extending to the base of the 5th metatarsal

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Description

Test your knowledge on the anatomy and functions of key leg muscles such as the Tibialis Anterior, Extensor Digitorum Longus, Peroneus Tertius, and Extensor Hallucis Longus. This quiz will cover origins, insertions, and actions of these muscles. Perfect for anatomy students and enthusiasts alike!