Wrist: Anatomical Name (Carpus), Bones, Common Conditions, and Function

What is another name of wrist?

The anatomical term for the wrist, specifically referring to the group of bones that form the wrist joint, is the carpus.

Understanding the Carpus: The Anatomical Name for the Wrist

While "wrist" is the commonly used term in everyday language, the more precise anatomical and medical term for this complex joint structure is the carpus. This term specifically refers to the collection of eight small bones, known as the carpal bones, that make up the wrist area. Understanding the carpus is fundamental to comprehending the intricate mechanics of the hand and forearm.

The Eight Carpal Bones: A Detailed Breakdown

The carpus is comprised of eight irregularly shaped carpal bones, arranged in two rows: the proximal row (closer to the forearm) and the distal row (closer to the hand). Their precise arrangement and articulations allow for the wide range of motion and stability required by the hand.

• Proximal Row (from radial to ulnar side):
  • Scaphoid: Boat-shaped; commonly fractured.
  • Lunate: Moon-shaped; frequently dislocated.
  • Triquetrum: Pyramid-shaped; articulates with the pisiform.
  • Pisiform: Pea-shaped; a sesamoid bone embedded in the flexor carpi ulnaris tendon.
• Distal Row (from radial to ulnar side):
  • Trapezium: Saddle-shaped; articulates with the thumb metacarpal, crucial for thumb opposition.
  • Trapezoid: Smallest of the distal row.
  • Capitate: Largest carpal bone; centrally located.
  • Hamate: Hook-shaped; provides attachment for muscles and ligaments.

These bones articulate with the radius and ulna of the forearm proximally, and with the metacarpal bones of the hand distally, forming several key joints that contribute to wrist movement.

Clinical Significance and Common Carpal Conditions

Knowledge of the carpus is vital in clinical practice, as this region is susceptible to various injuries and conditions. Understanding the specific carpal bones and their anatomical relationships helps in diagnosing and treating issues affecting the wrist.

• Carpal Tunnel Syndrome: A common condition where the median nerve, passing through the carpal tunnel (a passageway formed by carpal bones and the transverse carpal ligament), becomes compressed.
• Scaphoid Fractures: The scaphoid bone is the most frequently fractured carpal bone, often due to a fall onto an outstretched hand. Due to its unique blood supply, these fractures can be slow to heal.
• Wrist Sprains and Ligament Injuries: Ligaments connect the individual carpal bones to each other and to the forearm and hand bones, providing stability. Trauma can lead to sprains or more severe ligamentous tears.
• Ganglion Cysts: Non-cancerous lumps that most commonly develop on the back of the wrist, often originating from a joint capsule or tendon sheath.

Role of the Carpus in Movement and Function

The carpus, or wrist, is a highly mobile and adaptable joint that plays a critical role in the overall function of the upper limb. Its complex structure allows for:

• Flexion and Extension: Bending the hand forward and backward.
• Radial and Ulnar Deviation: Moving the hand side-to-side (towards the thumb or little finger).
• Circumduction: A combination of all these movements, allowing the hand to move in a circular motion.

These movements are essential for countless daily activities, from fine motor tasks like writing and typing to powerful movements such as lifting and gripping. The carpus acts as a crucial link, transmitting forces between the forearm and the hand, and enabling the precise positioning required for effective hand use.

Conclusion

While "wrist" is the commonly understood term, the anatomical name carpus precisely defines the collection of eight bones that form this critical joint. This intricate bony structure, along with its associated ligaments and muscles, provides the necessary mobility, stability, and force transmission capabilities that are fundamental to the diverse functions of the human hand. For anyone delving into the science of human movement, understanding the carpus is a cornerstone of anatomical knowledge.