Trapezoid at a glance
- What it is
- A small wedge-shaped carpal bone of the distal row.
- Location
- Lies between the trapezium and capitate, with the scaphoid proximally and the second metacarpal distally.
- Function
- Transmits force from the index finger to the wrist.
- Body system
- Skeletal · paired (left and right)
- FMA ID
- FMA24445 (Foundational Model of Anatomy)
Key facts
- It is the smallest bone of the distal carpal row.
- It is wedge-shaped, wider on its dorsal surface, and fits into a notch in the base of the second metacarpal, making the index-finger carpometacarpal joint almost immobile.
Structures next to the trapezoid
The nearest named structures in the 3D model, measured from the centre of each part:
- Dorsal carpal branch of radial artery · cardiovascular
- Trapezium · skeletal
- Deep palmar arch · cardiovascular
- Capitate · skeletal
- Scaphoid · skeletal
- Superficial palmar arterial arch · cardiovascular
- Oblique head of adductor pollicis · muscular
- Abductor pollicis brevis · muscular
- Flexor pollicis brevis · muscular
- Dorsal carpal branch of ulnar artery · cardiovascular
References
- Foundational Model of Anatomy: Trapezoid (FMA24445). 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.