Upper limb 2 Flashcards
What is a nerve plexus
when peripheral spinal nerve roots merge and split to form a network of nerves from which new multi segmented nerves arise
What spinal nerves are involved in the brachial plexus
C5 to T1
describe how the superior, middle and inferior trunk are formed
superior trunk - from C5 and C6 middle trunk - just C7 as the middle trunk inferior trunk - C8 and T1
How is the lateral cord produced
anterior division from superior and middle trunks
What 2 things do each trunk divide into
anterior and posterior divisions
How is the medial cord produced
single anterior division from the inferior cord
How is the posterior cord produced
all 3 of the posterior divisions of the trunks merge to form the posterior cord
what are the 2 mains groups of nerves that branch off from the brachial plexus
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
what are the 2 subdivisions of the infraclavicular nerves
1) branches to individual muscles 2) large terminal branches that innervate many muscles
What branch is the musculocutaneous nerve originate from
its a TERMINAL nerve from the lateral branch
What muscles does the musculocutaneous nerve innervate
anterior muscles, specifically: biceps and brachialis muscle
what does the musculocutaneous nerve pierce
coracobrachialis
Other than muscles what does the musculocutaneous nerve innervate
lateral cutaneous nerve innervates lateral arm
Draw on the arm what part of it is innervated by the lateral cutaneous nerve of the musculocutaneous nerve
in supination, about the lateral 1/3 of the arm
In pronation, very little of the lateral side of the arm
think about where the ulnar nerve supplies
What branch of which cord is the ulnar nerve
terminal branch of the medial nerve
Where does the ulnar nerve go behind and why is this relevant
behind the medial epicondyle of the humerus (easily damaged
What does the ulner nerve innervate that is not muscle
cutaneous innervation of medial hand
What muscles does the ulnar nerve innervate
flexor carpi ulnaris and medial flexor digitorum profundus
Speficially what cutaneous innervate does the ulnar nerve give
little finger and medial half of the ring finger
Where does the median nerve originate from
later and medial cords
how does the ulnar nerve enter the wrist
carpal tunnel
What muscles does the medial nerve innervate
all the anterior muscles of the forearm EXCEPT:
flexor carpi ulnaris
medial half of flexor digitorum profundis
innervates some intrinsic hand muscles
What is the supply of sensory innervation from medial nerve
later 3 and a half digits
Where does the auxillary nerve originate from
posterior cord
What does the auxillary nerve innervate
deltoid muscle and upper lateral aspect of the arm
Where does the radial nerve originate from
posterior cord
Describe radial nerve innervation and its journey
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
summarise the sensory innervation of the hand
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
when does the subclavian artery become the axillary artery
when it has travelled under the clavicle
what artery supplies the shaft of the humerus
anterior and posterior circumflex humoral arterie
what the largest branch of the brachial artery
profunda brachii
