Big Nerves Of Brachial Plexus Flashcards
Pathway of the musculocutaneous nerve
Pierces the coracobrachialis (medial to lateral) and emerges on the anterior surface
Runs between the brachialis and biceps muscle bodies
Pierces the brachial fascia to end and continues
Muscles innervated by the musculocutaneous nerve
Biceps brachii
Coracobrachialis
Brachialis
What is the musculocutaneous nerve sensory to?
Lateral antebrachium (lateral forearm)
The median nerve is formed by:
The medial and lateral branches of the lateral and medial cords, forms anterior to the axillary artery
Pathway of the median nerve
Runs on lateral surface of the brachial artery.
Crosses the brachial artery approx mid-arm to the medial side and comes in contact with the brachialis muscle
Enters the cubital fossa deep to the bicipital aponeuroses and median cubital vein
Innervation of the muscles
No branches in the arm but is a major player in the forearm and hand
Sensory of the median nerve
Hand- radial 2/3rds of the palm and Dortmund of the 2nd 3rd and radial half of the 4th distal to the interphalangeal joint
Ulnar nerve is a continuation of:
The medial cord on the medial aspect of the axillary artery
Pathway of the ulnar nerve
Runs anterior to the insertion of the teres major and long head of the triceps on the medial aspect of the axillary/brachial artery.
Accompanies the profunda brachii artery at its origin and moves medically to pierce the medial intermuscular septum with the superior ulnar collateral artery to enter the forearm between the heads of the pronator teres.
The musculocutaneous nerve changes to:
Lateral Cutaneous Nerve of the Forearm- runs along the cephalic vein
Medial brachial and medial antebrachial cutaneous nerves (sensory) originate from the:
Medial cord proximal to the formation of the ulnar nerve.
Can be confused for the ulnar nerve*
Sensory of the ulnar nerve:
the medial surface of the arm and forearm as the sensory branch names indicate
Radial nerve is formed by:
Posterior cord, posterior to the axillary artery
Pathway of the radial nerve
Begins to the axillary artery, medial to the humerus, anterior to the subscapularis muscle.
Crosses the latissimus dorsi tendon to run ant to the long head of the triceps muscle.
Passes through the trangular interval formed by the long and medial heads of the triceps and the tendon of the teres major, along with the profunda brachii branch of the axillary artery (deep brachial artery)
Enters the spiral groove of the humerus with the profunda, proper to the groove it innervates the long and lateral heads of the triceps
Where does the posterior cutaneous nerve of the arm form
Long head of the triceps muscle
In the spiral groove, the radial nerve supplies:
Branches to the medial head of the triceps and anconeus. It also supplies sensory branches to the posterior arm and forearm
After exiting the spiral groove, the radial nerve:
Pierces the lateral intermuscular septum to run between the brachialis and brachioradialis muscles to the cubital fossa
It then spilts into a deep muscular branch and a superficial sensory branch
Muscles innervated by the radial nerve
Posterior compartment muscles of the arm: Triceps and anconeus
Sensory of the radial nerve
Lateral dorsal of the hand and proximal 1/2 of the 2nd and 3rd digits
Axillary nerve is formed by:
The posterior cord forms posterior to the axillary artery
Pathway of axillary nerve
After branching from the posterior cord it passes laterally through the quadrangular space with the posterior circumflex humeral artery.
Sends a branch to the superior lateral brachium (up over the body of the deltoid muscle) as it circles the surgical neck of the humerus
Where does the axillary nerve terminate
As the branches to the teres minor and deltoid with a sensory branch to the glenohumeral joint
Muscles innervated by axillary nerve
Deltoid, teres minor
Sensory of the axillary nerve
Lateral aspect of the superior brachium
