1. Brachial Plexus Flashcards
The anterior rami of which spinal nerves make up the roots of the brachial plexus?
C5, C6, C7, C8, T1
The superior trunk is formed by what roots?
C5 + C6
The middle trunk is formed by what roots?
C7
The inferior trunk is formed by what roots?
C8 + T1
What forms the lateral cord?
Anterior divisions of superior and middle trunks
What forms the posterior cord?
Posterior divisions of superior, middle and inferior trunks
What forms the medial cord?
Anterior division of inferior trunk
The musculocutaneous nerve is a branch of which cord?
Lateral
What roots make up the musculocutaneous nerve?
C5,C6,C7
Musculocutaneous nerve supplies motor function to which muscles?
Biceps brachii, brachialis, coracobrachialis
The axillary nerve is a branch of which cord?
Posterior
What roots make up the axillary nerve?
C5,C6
Axillary nerve supplies motor function to which muscles?
Teres minor, deltoid
Axillary nerve supplies sensory to which area?
‘regimental badge area’- inferior deltoid
How can the axillary nerve be damaged? What is the clinical sign?
Humeral neck fracture/dislocation
Flattened deltoid
The median nerve is formed by the union of which two cords?
Lateral + medial cords
What roots make up the median nerve?
C5,C6,C7,C8,T1
What muscles of the hand are supplied by the median nerve?
LOAF muscles: L- Lateral two lumbricals O- Opponens pollis A- Abductor pollis brevis F- Flexor pollis brevis
What other muscles apart from LOAF does the median nerve supply?
The flexors of the forearm
Median nerve supplies sensory to what aspect of the hand?
Palmar aspect of lateral 3.5 fingers
What does compression of the median nerve result in?
Carpal tunnel syndrome
The radial nerve is a branch of which cord?
Posterior
What roots make up the radial nerve?
C5,C6,C7,C8,T1
What muscles receive motor supply from the radial nerve?
Triceps + extensor muscles of the forearm
Radial nerve supplies sensory supply to where?
Anatomical snuff box, posterior aspect of the arm and forearm
How is the radial nerve injured? What is the clinical sign?
Humeral mid shaft fracture.
WRIST DROP
Ulnar nerve is a branch of which cord?
Medial
What roots make up the ulnar nerve?
C8,T1
Ulnar nerve supplies motor function to which muscles?
Intrinsic muscles of the hand except lOAF muscles
Flexor carpi ulnaris
Ulnar nerve supplies sensory to what aspect of the hand?
Palmar aspect of medial 1.5 fingers
How is the ulnar nerve damaged? What is the clinical sign?
Medial epicondyle fracture
CLAW HAND
What roots form the long thoracic nerve?
C5,C6,C7
Long thoracic nerve supplies motor to which muscle?
Serratus anterior
Damage to the long thoracic nerve gives which clinical sign?
Winged scapula
What is Erbs palsy? Which roots are affected?
Upper brachial plexus palsy. C5 + C6
Which nerves are affected in Erbs palsy?
Musculocutaneous, Axillary, Suprascapular
Name the muscles which are paralysed in Erbs palsy
Supraspinatus, infraspinatus, subclavius, biceps brachii, brachialis, coracobrachialis, deltoid and teres minor.
What sign is characteristic of Erbs palsy?
Waiters tip position
What is Klumpkes palsy? Which roots are affected?
Lower brachial plexus palsy. T1
What nerves are affected in Klumpkes palsy? What muscles area paralysed as a result?
Ulnar and median nerve.
All the muscles of the hand
What sign does klumpke’s palsy result in?
Claw hand
How does klumpke’s palsy typically occur?
Excessive abduction of the arm e.g. person catching a branch as they fall from a tree
what injuries can cause damage to median nerve?
Dislocation of lunate
Supracondylar fracture
Stab wound to axilla damages which nerve?
Musculocutaneous
