radial nerve

Question 1

What does the radial nerve supply?

Answer 1

• Triceps
• anconeus
• ECRL
• ECRB
• Brachioradialis

Question 2

Where does the radial nerve originate?

Answer 2

• Posterior cord of brachial plexus C5-T1
• Behind axillary artery

Question 3

describe the course of radial nerve

Answer 3

• Posterior wall axilla
  
  • courses on post wall of axila on subscapularis, lat dorsi and teres major
  • 3 branches
    
    • post cutaneous n to arm
    • branch to long head of triceps
    • branch to medial head of triceps
• Triangular interval
  
  • ​thru triangular interval w profunda brachii artery in post compartment between long head of triceps and humerus
• Spiral groove
  
  • thru spiral groove between lateral/medial heads of triceps
    
    • safe zone post of 10cm distal to lateral acromium and 10cm prox to lateral epicondyle
    • branches to
      
      • inf cutaneous n to arm
      • post cutaneous n of forearm
      • branch to lat head of triceps
      • branch to med head tricpes/aconeus
  • Lateral muscular septa
    
    • pass thru lat intermsucular septa never less than 7.5cm above distal articular surface
    • runs between brachioradialis and brachialis- ant to lat epicondyle
    • branches to lateral brachialis, brachioradialis, ERCL.ERCB
  • Teminates at radiohumeral joint into
    
    • Superficial sensory branch
    • Deep Branch= PIN
    • ERCB branch

Question 4

What is the muscle supply of PIN?

Answer 4

• Extensor digitorium communis
• Supinator
• EDM
• ECU
• Abductor Pollicis Longus
• EPL
• EPB
• Extensor indicis proprosis- terminal branch**

Question 5

Describe the course of the PIN ?

Answer 5

• Originate at radiohumeral joint from the radial nerve
• Arcade of Frosche at radial head
  
  • dives under supinator, thickened edge of supinator
• forearm posterior compartment
  
  • winds around radial neck within susbtance of muscle to posterior compartment of forearm
• Interosseous membrane
  
  • reaches interosseous membrane of forearm and end in sensation to dorsal wrist capsule
• dorsal wrist capsule

Question 6

describe the course of the superificial sensory radial nerve

Answer 6

• originates form radial nerve proper at level of radiocapitellar joint
• Under brachioradialis
  
  • runs distally in forearm beneath BR, lateral to radial artery
• Forearm deep fascia
  
  • pierces deep fascia of forearm between BR and ERCL approx 7cm prox to radiocapal joint (9cm prox to radial styloid)
• Terminal branches
  
  • divides into dorsal/palmar branches
  • dorsal lies 103cm radial to lister’s tubercle
  • palmar branch passes within 2cm of 1st dorsal compartment, directly over EPL
  • supplies dorsolateral thumb