The Carpal tunnel, Guyon's canal and the anatomical snuffbox Flashcards
What is the carpal tunnel?
A narrow passageway on the anterior (palmar) surface of the wrist that serves as an entrance to the palm of numerous tendon and the median nerve
What makes up the deep border of the carpal tunnel?
Carpal bones
What makes the superficial border of the carpal tunnel?
Flexor retinaculum (Transverse carpal ligament)
Where does the flexor retinaculum (transverse carpal ligament) attach laterally (radial)?
Scaphoid + Trapezium
Where does the flexor retinaculum (transverse carpal ligament) attach medially (ulnar)?
Hook of hamate + Pisiform
Which structures passes through the carpal tunnel?
- Flexor pollicis longus tendon
- Flexor digitorum superficialis tendons x4
- Flexor digitorum profundus tendons x4
- Median nerve
Describe the arrangement of the FDS tendons as they pass through the carpal tunnel
Tendons to the middle finger and ring finger pass superficially to the index and little finger
Where does the palmar cutaneous branch of the median nerve branches and what is the clinical relevance of this?
- Proximal to the carpal tunnel
- In carpal tunnel syndrome, sensation is unaffected
What is the Guyon’s canal
A semi-rigid longitudinal canal in the wrist that allows passage for the ulnar nerve and the arteries of the hand (ulnar and radial)
Where is the Guyon’s canal relative to the carpal tunnel?
Superficial
What forms the roof of the Guyon’s canal?
Palmar carpal ligament
What is the clinical importance of Guyon’s canal?
Ulnar nerve compression
What is the anatomical snuff box (radial fossa)?
A triangular depression on the radial aspect of the dorsum of the hand
What are the contents of the anatomical snuff box?
- Radial artery
- Superficial branch of the radial nerve
- Cephalic vein
What forms the lateral (radial) border of the anatomical snuff box?
- Tendons of abductor pollicis longus
- Extensor pollicis brevis
