Brachial plexus Flashcards
What does the brachial plexus supply?
The upper limb
Which spinal nerve roots are involved?
anterior rami of C5, C6, C7, C8, T1
Really tired drink coffee now
Roots Trunks Divisions Cords Nerves
Trunks: Superior, middle and inferior
Superior: C5 + C6
Middle: C7
Inferior: C8 + T1
Divisions
Anterior and posterior
Cords
Named according to their relationship to the axillary artery
Outer = lateral
Middle = posterior
Inner = medial
Which nerves make up the M shape?
Musculucutaneous nerve - lateral
Median nerve - from branches of lateral and medial cords
Ulnar nerve - Continues from medial cord
Which nerves does the posterior cord give rise to?
Axillary nerve
Radial nerve
Which nerves does the lateral for give rise to?
Musculocutaneous nerve
Median nerve
Which nerves does the medial cord give rise to?
Ulnar nerve
Median nerve
Where are roots and trunks located?
Between anterior and middle scalene muscles in the root of the neck
Where are divisions located?
Posterior to the subclavian vessels in the root of the neck
Where are cords located?
They lie around the axillary artery
Musculocutaneous nerve - route
Pierces through the coracobrachialis muscle
Musculocutaneous nerve - what does it supply?
Muscles of the anterior compartment of the arm
- Coracobrachialis
- Biceps brachii
- Brachialis
Median nerve - route
Comes down the medial aspect of the arm then crosses anteriorly at the elbow (cubital fossa) and enters the forearm, then passes through the wrist and into the hand
Median nerve - what does it supply?
Motor nerve fibres supply the majority of the anterior forearm muscles and the thenar eminence muscles
Somatic nerve fibres supply the LATERAL 3 and a half fingers of the palmar aspect of the hand and the skin over the nailbed of thumb, index, middle finger and lateral half of ring finger
Ulnar nerve - route
Passes from the anterior compartment of the arm posterior to the medial epicondyle (via cubital tunnel and flexor carpi ulnaris) to the anterior compartment of the forearm. It then passes into the hand
Ulnar nerve - what does it supply?
Motor nerve fibres supply the majority of muscles in the hand (apart from thenar eminence), also supplies some of the muscles of the anterior forearm
Somatic nerve fibres supply the medial 1 and a half fingers
Axillary nerve - route
Enters the posterior compartment of the arm.
Wraps around the posterior aspect of the surgical neck of the humerus
Located in the quadrangular space.
Lies superior to the radial nerve
Axillary nerve - what does it supply?
Deltoid muscle and teres minor muscle
Sensory nerve fibres supply the badge patch area (over the lateral aspect of the arm)
Radial nerve - route
From the radial groove of the humerus to the lateral aspect of the cubital fossa
Radial nerve - what does it supply?
Motor nerve fibres supply the posterior compartment of the arm (triceps) and forearm
Sensory nerve fibres supply the skin over the lateral aspect of the dorsum of the hand
RADIAL NERVE ALWAYS STAYS POSTERIOR
What is the deep branch of the radial nerve called? and what does it supply?
Posterior interosseous nerve
Supplies the posterior compartment of the forearm
