Abductor pollicis longus at a glance
- What it is
- A deep forearm extensor that forms the lateral border of the anatomical snuffbox.
- Location
- Origin: posterior surfaces of the ulna, radius and interosseous membrane. Insertion: lateral side of the base of the 1st metacarpal.
- Function
- Abducts the thumb and extends it at the carpometacarpal joint; also helps abduct the hand.
- Body system
- Muscular · paired (left and right)
- FMA ID
- FMA38516 (Foundational Model of Anatomy)
Key facts
- Innervation: posterior interosseous nerve (C7–C8)
- Its tendon runs in the first dorsal compartment with extensor pollicis brevis
Clinical relevance
Inflammation of its tendon sheath, together with extensor pollicis brevis, causes de Quervain tenosynovitis.
Structures next to the abductor pollicis longus
The nearest named structures in the 3D model, measured from the centre of each part:
- Extensor digitorum · muscular
- Extensor digiti minimi · muscular
- Flexor digitorum superficialis · muscular
- Interosseous membrane of forearm · skeletal
- Palmaris longus · muscular
- Radial artery · cardiovascular
- Pronator quadratus · muscular
- Radius · skeletal
- Flexor pollicis longus · muscular
- Ulnar artery · cardiovascular
References
- Foundational Model of Anatomy: Abductor pollicis longus (FMA38516). EMBL-EBI Ontology Lookup Service.
- OpenStax. Anatomy and Physiology 2e, §11.2 Naming Skeletal Muscles. Rice University, 2022.
- Mitsuhashi N. et al. (2009). BodyParts3D: 3D structure database for anatomical concepts. Nucleic Acids Research 37, D782–D785. Data © The Database Center for Life Science, CC BY 4.0.
Related anatomy
Explore the whole body in the interactive 3D human anatomy model, or browse the A–Z list of human structures.