Nerves of Upper limb

Question 1

Lateral cord of Brachial plexus

Answer 1

musculocutaneous n

median n

Question 2

Medial cord of Brachial plexus

Answer 2

median n
ulnar n
medial brachial cutaneous n
medial antebrachial cutaneous n

Question 3

Posterior cord of Brachial plexus

Answer 3

axillary nerve

radial nerve

Question 4

Musculocutaneous nerve

Answer 4

• pierces coracobrachial muscle ⇒ run between biceps brachii and brachialis ⇒ sensory end-branch lateral ante brachial cutaneous nerve become superficial in cubital fossa ⇒ radially
• motor innervation: flexors of arm
• skin innervation: lateral forearm

Question 5

Median nerve

Answer 5

• fork anterior to axillary artery ⇒ run in medial bicipital groove ⇒ cubital fossa ⇒ under pronator teres orgin ⇒ under flexor digitorum superficialis ⇒ trough carpal tunnel ⇒ in palm between superficial palmar arch and tendon of flexor digitorum spf
• branches in forearm: sensory palmar branch
• branches in palm: common palmar digital nerves ⇒ proper palmar digital nerves
• motor inenrvation: flexors of forearm, 1-2 radial lumbricals, abductor pollicis brevis, opponens pollicis, flexor pollicis brevis
• sensory innervation: radial part of skin of palm ⇒ 7 radial finger halves on palmar side + distal half on dorsal side

Question 6

Medial brachial cutanous nerve

Answer 6

• sensory innervation: skin of medial surface of arm

Question 7

Medial antebrachial cutanous nerve

Answer 7

• sensory innervation: medial side of forearm

- runs in medial bicipital groove ⇒ pierces brachial fascia ⇒ subcutaneous

Question 8

Ulnar nerve

Answer 8

• runs medial to brachial a. ⇒ pierces medial intermuscular septa ⇒ extensor compartment ⇒ around medial epicondyle ⇒ between flexor carpi ulnaris + pronator teres ⇒ guyon’s canal
• Branches in forearm: dorsal branch⇒ dorsal digital nerves
• Branches in hand: deep branch + superficial branch ⇒ common palmar ⇒ proper palmar digital nerve
• motor innervation: flexor carpi ulnaris, flexor digitorum produndus, ulnar lumbricals, hypothenar muscles, adductor pollicis brevis, flexor pollicis brevis
• sensory innervation: skin of ulnar part of palm + dorsum

Question 9

Axillary nerve

Answer 9

• through quadrangular axillary space ⇒ surgical neck of humerus
• sensory branch: superior lateral brachial cutaneous n
• motor innervation: deltoid, teres minor
• sensory innervation: upper lateral surface of arm

Question 10

Radial nerve

Answer 10

• behind axillary and brachial a⇒ groove of radial nerve ⇒ spirally turns around humerus ⇒ pierces lateral inter muscular septa ⇒ run under brachioradialis ⇒ turns dorsal above anatomical snuff box
• branches in arm: posterior brachial cutaneous n., lateral inferior brachial cutaneous n., posterior antebrachial cutaneous n + deep and superficial + 5 dorsal digital nerves
• motor innervation: extensors of arm and forearm
• sensory inenrvation: posterior surface of arm and forearm, 5 radial finer halves on dorsal side of palm