The structure indicated is the pisiform bone
of the hand.
There are three groups of bones
in the hand:
- Carpal bones (8 in total)
- Metacarpal bones
The carpal bones are separated into two rows
- Proximal row
- Distal row
The pisiform bone is one of four bones
in the proximal row of carpals (scaphoid, lunate, triquetral, pisiform
). The pisiform bone is a tiny sesamoid
bone located in the tendon of the flexor carpi ulnaris
muscle. It articulates with the palmar surface of the triquetral
Learn more about the anatomy of the bones of the hand
in this tutorial.