Definition

Noun: 1. A small pea-shaped carpal bone: The pisiform bone is a small, sesamoid bone located in the proximal row of the wrist (carpus) on the ulnar side. It is unique among the carpal bones as it primarily articulates only with the triquetral bone (triquetrum) and acts as a sesamoid bone within the tendon of the flexor carpi ulnaris muscle.

Usage Examples

• Noun:
  • The pisiform bone provides a protective function and a mechanical advantage for the attached tendon.
  • Fracture of the pisiform bone is relatively uncommon but can cause significant pain in the heel of the hand.
  • On the X-ray, you can see the pisiform bone positioned anterior to the triquetral.

Advanced Usage

• "Pisiform" as an adjective: The term "pisiform" itself is an adjective meaning "pea-shaped." It is used to describe the bone's morphology.
  • The pisiform structure is palpable on the inner side of the wrist.

Variants and Related Words

• Pisiform (adj.): Having the shape of a pea.
• Triquetral bone / Triquetrum (n.): The carpal bone with which the pisiform articulates.
• Carpal bones (n.): The collective term for the eight small bones that make up the wrist, including the pisiform.
• Sesamoid bone (n.): A bone embedded within a tendon, a category which includes the pisiform.

Synonyms

• Os pisiforme: The Latin anatomical term.
• Pisiforme: A less common English variant.

Related Anatomical Structures

• Flexor carpi ulnaris tendon: The tendon in which the pisiform bone is embedded.
• Pisotriquetral joint: The specific joint formed between the pisiform and triquetral bones.

Noun

1. a small wrist bone that articulates only with the triquetral