Upper limb 2

Question 1

What is a nerve plexus

Answer 1

when peripheral spinal nerve roots merge and split to form a network of nerves from which new multi segmented nerves arise

Question 2

What spinal nerves are involved in the brachial plexus

Answer 2

C5 to T1

Question 3

describe how the superior, middle and inferior trunk are formed

Answer 3

superior trunk - from C5 and C6 middle trunk - just C7 as the middle trunk inferior trunk - C8 and T1

Question 4

How is the lateral cord produced

Answer 4

anterior division from superior and middle trunks

Question 5

What 2 things do each trunk divide into

Answer 5

anterior and posterior divisions

Question 6

How is the medial cord produced

Answer 6

single anterior division from the inferior cord

Question 7

How is the posterior cord produced

Answer 7

all 3 of the posterior divisions of the trunks merge to form the posterior cord

Question 8

what are the 2 mains groups of nerves that branch off from the brachial plexus

Answer 8

supraclavicular nerves= branch off from proximal part of the plexus superior to the clavicle to supply scapular muscle infraclavicular nerves = branch off from distal parts of plexus, inferior to the clavicle

Question 9

what are the 2 subdivisions of the infraclavicular nerves

Answer 9

1) branches to individual muscles 2) large terminal branches that innervate many muscles

Question 10

What branch is the musculocutaneous nerve originate from

Answer 10

its a TERMINAL nerve from the lateral branch

Question 11

What muscles does the musculocutaneous nerve innervate

Answer 11

anterior muscles, specifically: biceps and brachialis muscle

Question 12

what does the musculocutaneous nerve pierce

Answer 12

coracobrachialis

Question 13

Other than muscles what does the musculocutaneous nerve innervate

Answer 13

lateral cutaneous nerve innervates lateral arm

Question 14

Draw on the arm what part of it is innervated by the lateral cutaneous nerve of the musculocutaneous nerve

Answer 14

in supination, about the lateral 1/3 of the arm

In pronation, very little of the lateral side of the arm

Question 15

think about where the ulnar nerve supplies

What branch of which cord is the ulnar nerve

Answer 15

terminal branch of the medial nerve

Question 16

Where does the ulnar nerve go behind and why is this relevant

Answer 16

behind the medial epicondyle of the humerus (easily damaged

Question 17

What does the ulner nerve innervate that is not muscle

Answer 17

cutaneous innervation of medial hand

Question 18

What muscles does the ulnar nerve innervate

Answer 18

flexor carpi ulnaris and medial flexor digitorum profundus

Question 19

Speficially what cutaneous innervate does the ulnar nerve give

Answer 19

little finger and medial half of the ring finger

Question 20

Where does the median nerve originate from

Answer 20

later and medial cords

Question 21

how does the ulnar nerve enter the wrist

Answer 21

carpal tunnel

Question 22

What muscles does the medial nerve innervate

Answer 22

all the anterior muscles of the forearm EXCEPT:

flexor carpi ulnaris

medial half of flexor digitorum profundis

innervates some intrinsic hand muscles

Question 23

What is the supply of sensory innervation from medial nerve

Answer 23

later 3 and a half digits

Question 24

Where does the auxillary nerve originate from

Answer 24

posterior cord

Question 25

What does the auxillary nerve innervate

Answer 25

deltoid muscle and upper lateral aspect of the arm

Question 26

Where does the radial nerve originate from

Answer 26

posterior cord

Question 27

Describe radial nerve innervation and its journey

Answer 27

innervates all arm and forearm posterior muscles

It divides to give superficial and deep branches anterior to the later epicondyle of the elbow. Before this it was running in the radial groove of the shaft of the humerus

Superficial innervates dorsum of the hand (sensory )

deep branch motor inervation to posterior forearm muscles

Question 28

summarise the sensory innervation of the hand

Answer 28

ulner nerve innervates anterior and posterior medial 1 and a 1/2 digits

median nerve innervates lateral anterior 3 and a half digits

radial nerve innervates posterolateral part of hand

Question 29

when does the subclavian artery become the axillary artery

Answer 29

when it has travelled under the clavicle

Question 30

what artery supplies the shaft of the humerus

Answer 30

anterior and posterior circumflex humoral arterie

Question 31

what the largest branch of the brachial artery

Answer 31

profunda brachii