Nerves 1: Arm and Thigh Flashcards
Musculocutaneous nerve: motor fibres?
flexors of the arm (BBC)
+ biceps brachii
+ brachioradialis
+ coracobrachialis
Musculocutaneous nerve: becomes which nerve of forearm?
lateral cutaneous nerve
Roots of musculocutaneous nerve?
C5/C6/C7
Roots of axillary nerve?
C5/C6
Axillary nerve: motor fibres supply?
deltoid and teres minor
Axillary nerve: sensory fibres supply?
skin over lower part of deltoids
Roots of radial nerve?
C5/C6/C7/C8/T1
Radial nerve: motor fibres supply?
all extensor muscles of arm and forearm
Radial nerve: sensory fibres supply?
posterior skin of arm, forearm and hand
Roots of axillary nerve?
C5/C6
Where does axillary nerve pass/lie?
+ posteriorly through the quadrangular space
+ lies on surgical neck of humerus with posterior circumflex artery
What branch of the axillary nerve supplies deltoid, teres minor and skin over lower part of deltoid?
superior lateral brachial cutaneous nerve
What does injury to the axillary nerve result in?
+ reduced abduction (beyond 15degrees)
+ muscular atrophy (flattened shoulder)
+ loss of sensation near inf. deltoid
What is the role of coracobrachialis?
+ flex and adduct arm
+ resists dislocation of shoulder and GH joint
What is the role of biceps brachii?
+ flex
+ resist dislocation of forearm
+ supination
Where does the radial nerve pass?
+ POSTERIORLY through lower triangular space with profunda brachii artery
What does the radial nerve divide into once in forearm?
+ superficial cutaneous branch
+ deep motor branch
What does the radial nerve innervate in the arm?
\+ triceps brachii \+ anconeus \+ extensor carpi radialis longus \+ extensor carpi radialis brevis \+ brachioradialis
Where does the radial nerve supply in the forearm as deep branch?
\+ extensor carpi radialis brevis \+ extensor digitorum \+ extensor digiti minimi \+ extensor carpi ulnaris \+ supinator
Where does the radial nerve supply in the forearm from posterior interosseous?
+ extensor indicis
+ abductor pollicis longus
+ extensor pollicis longus
+ extensor pollicis brevis
What does the median nerve supply?
flexors of the forearm
What would paralysis of extensor muscles of arm be a result of?
radial nerve injury - usually humeral shaft fracture
What is ‘wrist drop’ a presentation of?
radial nerve injury
