Anatomy Bones and Muscles · MU Pleven

230. Dorsum manus.

Covers the wrist region of the limb, including the anterior and posterior regions. It describes the skin, superficial and deep fascia, and the flexor retinaculum that forms the ulnar (Guyon's) canal, the radial carpal canal and the carpal tunnel, with their boundaries and contents. It then turns to the anatomical snuff box and the extensor retinaculum with its six osteo-fibrous canals.

Inside: 4 sections · 4 labelled pictures · 16 flashcards · 3 min

Topic 229 of 236 in the MU Pleven syllabus for Anatomy Bones and Muscles (Medicine, Year 2). The free AceMed note covers it in 4 sections, about 460 words (3 min of reading), with 16 flashcards.

In this note

  1. WRIST Region
  2. Anterior Region:
  3. Posterior Region
  4. Posterior Region:

Anterior Region:

1. Skin Characteristics:

  • Very fine and smooth.
  • Devoid of hair.

2 Superficial Fascia:

  • Contains very little fat.
  • Fixed to the deep fascia, especially around os pisiforme.

3. Deep Fascia:

  • Continuous with the antebrachial fascia.
  • Thickened by transverse fibrous strands forming a thick 1.5-2 cm wide transverse band.
  • Fuses with the retinaculum mm. flexorum.
  • The Retinaculum transforms the carpal groove into carpal canals:
  • It's radial end sends a thin fibrous septum inwards that insets onto the bones & forms Radial Carpal Canal.
  • u medial end forms Ulnar Carpal canal (lateral to the bones btw the retinaculum & superficial fascia)
  • In the middle forms Carpal tunnel.

The ulnar canal (Guyon's canal) is a passage through the split layers of the flexor reti-naculum located on the medial side of the wrist.

Boundaries

  1. 1 Medially: pisiform bone
  2. 2 Laterally: hamulus (hook) of hamate bone
  3. 3 Dorsally: flexor retinaculum
  4. 4 Superficially: palmaris brevis and part of flexor retinaculum

Content

  1. 5 Ulnar artery
  2. 6 Ulnar veins
  3. 7 Ulnar nerve

The carpal tunnel is formed by the carpal bones and a thick ligament called the flexor retinaculum. These walls do not allow expansion of this space. This causes the median nerve to be more susceptible to compression as it courses through the carpal tunnel. Compression of the median nerve in the carpal tunnel is known as carpal tunnel syndrome and is the most common entrapment syndrome. The carpal canal is subdivided by a fibrous septum into two subspaces: the smaller radial region and the larger ulnar region.

Boundaries

  1. 1 Medially: ulnar eminence of the wrist
  2. 2 Laterally: radial eminence of the wrist
  3. 3 Dorsally: bones of the wrist
  4. 4 Frontally: flexor retinaculum

Content

Ulnar part

  1. 5 Median nerve
  2. 6 Tendon of flexor pollicis longus
  3. 7 Tendons of flexor digitorum superficialis
  4. 8 Tendons of flexor digitorum profundus

Radial part

  1. 9 Tendon of flexor carpi radialis

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