Anatomy Bones and Muscles · MU Pleven

160. Radial nerve.

Covers the radial nerve from its origin in the posterior cord of the brachial plexus through its course down the back of the arm and forearm. It describes the passage through the lower triangular space, the spiral groove and the lateral intermuscular septum, then lists the branches in order: those given off before the spiral groove, those within it, and the superficial and deep terminal branches with the muscles and skin each supplies.

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

Topic 159 of 236 in the MU Pleven syllabus for Anatomy Bones and Muscles (Medicine, Year 2). The free AceMed note covers it in 3 sections, about 236 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 3 1/2 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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