Anatomy study note · Upper limb

Extensor pollicis longus

A deep extensor whose tendon hooks round the dorsal tubercle of the radius and forms the medial border of the anatomical snuffbox.

Key points

• Back of ulna → base of the distal phalanx of the thumb.
• Deep radial nerve.
• Medial border of the snuffbox.
• Ruptures after Colles fracture or in RA.
• Limb muscles: in situ from limb-bud mesenchyme.
• Upper limb bud C4–T2; lower limb bud L2–S2.
• Skeletal muscle: multinucleated, peripheral nuclei, striated.
• Epimysium → perimysium → endomysium.

The full note in the atlas also covers

Origin · Insertion · Action · Nerve supply · Histology · Development · Clinical notes

Sign in free to see it on the 3D model, read the full note and practise questions on it.

Written from

• Snell’s Clinical Anatomy by Regions, 10th ed., ch. 3, PDF pp. 309, 463
• Inderbir Singh’s Human Embryology, ch. 7, PDF p. 109; ch. 10, PDF pp. 142–145
• BRS Cell Biology & Histology, 7th ed., ch. 8, PDF pp. 135–144

More from the upper limb

• Extensor retinaculum of the wrist
• Flexor carpi radialis
• Flexor carpi ulnaris
• Flexor digitorum profundus
• Flexor digitorum superficialis
• Flexor pollicis longus
• Flexor retinaculum and carpal tunnel
• Humerus
• Hypothenar muscles
• Infraspinatus
• Intercarpal and carpometacarpal joints
• Interossei of the hand

Privacy policy · Designed by DATXOC LLC.