First metacarpal bone at a glance
- Also called
- first metacarpal
- What it is
- The thumb metacarpal, shorter and stouter than the others. One of the five long bones of the palm.
- Location
- Lies between the carpal bones of the wrist and the proximal phalanx of its finger, with a base proximally and a rounded head forming the knuckle.
- Function
- Forms the framework of the palm and transmits forces from the fingers to the wrist.
- Body system
- Skeletal · paired (left and right)
- FMA ID
- FMA24465 (Foundational Model of Anatomy)
Key facts
- Its base forms a saddle joint with the trapezium, giving the thumb its wide range of motion including opposition.
- It lies rotated about 90 degrees relative to the others.
Clinical relevance
A fracture-dislocation at its base is called a Bennett fracture.
Structures next to the first metacarpal bone
The nearest named structures in the 3D model, measured from the centre of each part:
- Flexor pollicis brevis · muscular
- Superficial head of flexor pollicis brevis · muscular
- Abductor pollicis brevis · muscular
- Oblique head of adductor pollicis · muscular
- Opponens pollicis · muscular
- Arteria princeps pollicis · cardiovascular
- Transverse head of adductor pollicis · muscular
- Extensor indicis · muscular
- Trapezium · skeletal
- Second metacarpal bone · skeletal
References
- Foundational Model of Anatomy: First metacarpal bone (FMA24465). EMBL-EBI Ontology Lookup Service.
- OpenStax. Anatomy and Physiology 2e, §7.1 Divisions of the Skeletal System. 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.