5 main nerves

• Axillary nerve

  1. Arises from ventral rami of C5 and 6, superior trunk (posterior division) and posterior cord

  2. Passes posterior to axillary artery and anterior to subscapularis

  3. Passes close to inferior aspect of shoulder joint and through quadrilateral space

  4. Winds around surgical neck of humerus

  
• Axillary nerve

  • Motor supply: Deltoid and teres minor
  • Sensory supply: Skin on lateral aspect of shoulder and articular branches to shoulder joint

  
• Musculocutaneous nerve

  1. Arises from ventral rami of C5, 6 and 7, superior and middle trunks (anterior divisions) and lateral cord

  2. Lies lateral to axillary artery in axilla

  3. Descends into arm by piercing coracobrachialis

  4. Runs distally between biceps and brachialis

  5. At elbow becomes lateral cutaneous nerve of forearm

  
• Musculocutaneous nerve

  • Motor supply: Biceps brachii, medial part brachialis and coracobrachialis
  • Sensory supply: Skin on lateral half of forearm down to base of thumb

  
• Median nerve

  1. Arises from C5, 6, 7, 8, T1, superior, middle and inferior trunks (anterior divisions) and lateral and medial cords

  2. Enters arm from axilla at inferior margin of teres major

  3. Passes down medial side of arm under cover of biceps brachii

  4. Lies anterior to elbow joint in cubital fossa

  5. Enters forearm between 2 heads of pronator teres

  6. Runs below tendinous arch of FDS and between FDS and FDP to wrist

  7. Becomes superficial above wrist between tendons of FDS and FCR

  8. Travels under flexor retinaculum to enter hand, passing anterior to long flexor tendons

  9. Divides into lateral (recurrent) and medial branches in hand

  
• Median nerve


  • Motor supply: Pronator teres, FCR, palmaris longus and FDS
  • Sensory supply: Articular branches to elbow joint

  
• Ulnar nerve

  1. Arises from ventral rami of C8 and T1 (and occasionally C7), inferior trunk (anterior division) and medial cord

  2. Enters arm medial to axillary artery, descends arm medial to brachial artery and anterior to triceps

  3. Half way down arm passes posteriorly, piercing medial intermuscular septum

  4. At elbow passes behind medial epicondyle of humerus

  5. In forearm passes between 2 heads of FCU

  6. Descends down medial side of forearm between FCU and FDP

  7. At wrist lies lateral to FCU tendon and medial to ulnar artery

  8. Crosses over flexor retinaculum into hand where it divides into superficial and deep branches

  
• Ulnar nerve

  • Motor supply: FCU and medial ½ FDP
  • Sensory supply: Articular branch to elbow

  
• Radial nerve

  1. Arises from C5, 6, 7, 8, T1, superior, middle and inferior trunks (posterior divisions) and posterior cord

  2. Lies posterior to axillary artery in axilla, passes anterior to tendons of subscapularis, latissimus dorsi and teres major

  3. Enters posterior aspect of arm via triangular space

  4. Runs obliquely inferolaterally along radial groove on posterior aspect of humerus

  
• Radial nerve

  • Motor supply: None
  • Sensory supply: Skin on dorsolateral aspect of wrist and hand, dorsum of lateral 3½ digits as far as distal IP joints, articular branches to MCP and PIP joints