Anatomy · MU Sofia

PNS · 188. Radial nerve.

Covers the radial nerve from its origin in the posterior cord of the brachial plexus through its course in the axilla, arm and forearm. It describes the passage through the triangular space, the spiral groove and the lateral intermuscular septum, then lists the proximal, spiral-groove and terminal branches, separating the superficial sensory branch from the deep motor branch that winds round the radial neck. Four pictures accompany the text.

Inside: 3 sections · 4 labelled pictures · 10 flashcards · 2 min

Topic 172 of 264 in the MU Sofia syllabus for Anatomy (Dental Medicine, Year 2). The free AceMed note covers it in 3 sections, about 232 words (2 min of reading), with 10 flashcards.

In this note

  1. RADIAL NERVE
  2. Course :
  3. Branches :

RADIAL NERVE

  • The radial nerve arises from the posterior cord of the brachial plexus.
  • It runs down the posterior side of the arm & forearm.
  • Innervates the post. part of the upper limb.

* Lower triangular

bordered laterally by the shaft of the humerus and medially by lat. border of long head of triceps.

Course :

In axilla and arm:

  • Posterior to 3rd part of axillary a. and upper half of brachial a.
  • It passes through the lower triangular space to run in Post. compartments of the arm in the spiral groove. (of the humerus)
  • Pierces lateral intermuscular septum to go back to the ant. compartment in groove between brachialis & brachio-radialis muscles.
  • Anterior to the lateral epicondyle of humerus. It ends by giving a superficial (sensory) and deep (motor) terminal branches.

Branches :

Proximal to spiral groove: (3 branches

  • 2 muscular to triceps (Long & medial)
  • 1 Post. cutaneous of arm.

In the spiral groove: (5 branches)

  • 3 muscular: to triceps (lat. & med.) + anconeus.
  • 2 cutaneus: lower lat. of arm + post. cut. of forearm.

Superficial terminal :

lateral 2/3 of dorsum of hand and dorsal surface of lateral 3½ fingers except nail beds.

Deep terminal :

  • Reaches back of forearm by passing between two heads of supinator, winds around neck of the radius.
  • Supplies ext. carpi radialis brevis & supinator (before piercing)
  • Supplies the rest of the extensor compartment of the forearm (after piercing).

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