Abductor pollicis brevis at a glance
- What it is
- A thenar muscle on the lateral side of the thenar eminence.
- Location
- Origin: flexor retinaculum, tubercles of the scaphoid and trapezium. Insertion: lateral side of the base of the proximal phalanx of the thumb.
- Function
- Abducts the thumb, helping to initiate opposition.
- Body system
- Muscular · paired (left and right)
- FMA ID
- FMA37386 (Foundational Model of Anatomy)
Key facts
- Innervation: recurrent branch of the median nerve (C8–T1)
- It is the most superficial thenar muscle and is tested by lifting the thumb at right angles to the palm against resistance, a standard test of the median nerve.
- Blood supply: superficial palmar branch of the radial artery
Clinical relevance
Wasting of the thenar eminence is a sign of severe carpal tunnel syndrome.
Structures next to the abductor pollicis brevis
The nearest named structures in the 3D model, measured from the centre of each part:
- Opponens pollicis · muscular
- Flexor pollicis brevis · muscular
- Superficial head of flexor pollicis brevis · muscular
- First metacarpal bone · skeletal
- Oblique head of adductor pollicis · muscular
- Trapezium · skeletal
- Trapezoid · skeletal
- Extensor indicis · muscular
- Dorsal carpal branch of radial artery · cardiovascular
- Deep palmar arch · cardiovascular
References
- Foundational Model of Anatomy: Abductor pollicis brevis (FMA37386). 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.