Nerves 1: Arm and Thigh

Question 1

Musculocutaneous nerve: motor fibres?

Answer 1

flexors of the arm (BBC)
+ biceps brachii
+ brachioradialis
+ coracobrachialis

Question 2

Musculocutaneous nerve: becomes which nerve of forearm?

Answer 2

lateral cutaneous nerve

Question 3

Roots of musculocutaneous nerve?

Answer 3

C5/C6/C7

Question 4

Roots of axillary nerve?

Answer 4

C5/C6

Question 5

Axillary nerve: motor fibres supply?

Answer 5

deltoid and teres minor

Question 6

Axillary nerve: sensory fibres supply?

Answer 6

skin over lower part of deltoids

Question 7

Roots of radial nerve?

Answer 7

C5/C6/C7/C8/T1

Question 8

Radial nerve: motor fibres supply?

Answer 8

all extensor muscles of arm and forearm

Question 9

Radial nerve: sensory fibres supply?

Answer 9

posterior skin of arm, forearm and hand

Question 10

Roots of axillary nerve?

Answer 10

C5/C6

Question 11

Where does axillary nerve pass/lie?

Answer 11

+ posteriorly through the quadrangular space

+ lies on surgical neck of humerus with posterior circumflex artery

Question 12

What branch of the axillary nerve supplies deltoid, teres minor and skin over lower part of deltoid?

Answer 12

superior lateral brachial cutaneous nerve

Question 13

What does injury to the axillary nerve result in?

Answer 13

+ reduced abduction (beyond 15degrees)
+ muscular atrophy (flattened shoulder)
+ loss of sensation near inf. deltoid

Question 14

What is the role of coracobrachialis?

Answer 14

+ flex and adduct arm

+ resists dislocation of shoulder and GH joint

Question 15

What is the role of biceps brachii?

Answer 15

+ flex
+ resist dislocation of forearm
+ supination

Question 16

Where does the radial nerve pass?

Answer 16

+ POSTERIORLY through lower triangular space with profunda brachii artery

Question 17

What does the radial nerve divide into once in forearm?

Answer 17

+ superficial cutaneous branch

+ deep motor branch

Question 18

What does the radial nerve innervate in the arm?

Answer 18

\+ triceps brachii
\+ anconeus
\+ extensor carpi radialis longus
\+ extensor carpi radialis brevis
\+ brachioradialis

Question 19

Where does the radial nerve supply in the forearm as deep branch?

Answer 19

\+ extensor carpi radialis brevis
\+ extensor digitorum
\+ extensor digiti minimi
\+ extensor carpi ulnaris
\+ supinator

Question 20

Where does the radial nerve supply in the forearm from posterior interosseous?

Answer 20

+ extensor indicis
+ abductor pollicis longus
+ extensor pollicis longus
+ extensor pollicis brevis

Question 21

What does the median nerve supply?

Answer 21

flexors of the forearm

Question 22

What would paralysis of extensor muscles of arm be a result of?

Answer 22

radial nerve injury - usually humeral shaft fracture

Question 23

What is ‘wrist drop’ a presentation of?

Answer 23

radial nerve injury