Nerve and blood supply to the upper limb Flashcards
Stem artery
Subclavian artery supplies the upper limb
Right from brachiocephalic trunk
Left from arch of the aorta
Subclavian artery
Passes through scalene triangle over first rib
Divided into 3 parts by scalenus anterior
- 1st medical to muscle
- 2nd behind muscle
- 3rd lateral to muscle
Branches of subclavian artery
Dorsal scapular artery (from 2nd or 3rd part)
- contributes to scapular anastomosis
Thyrocervical trunk (to thyroid, cervical, scapular) - contribute to scapular anastomosis
End of subclavian artery
Ends as it crosses outer border of first rib
Becomes axillary artery
Axillary artery
Divided into 3 parts by pectoralis minor
- 1st medial to muscle
- 2nd behind muscle
- 3rd lateral to muscle
First and second parts closely associated with the brachial plexus
Ends at lower border of teres major
Becomes brachial artery
Axillary artery branches
Subscapular
- to scapular anastomosis
Ant/ pos circumflex humeral
- to neck/ shaft of humerus
Brachial artery
Superficial throughout arm
Supplies flexors
Large branch- profunda brachii artery
Contributes to anastomosis around elbow
Divides in cubital fossa
- radial artery
- ulnar artery
Profunda brachii artery
Accompanies radial nerve in spiral groove
Fracture to humerus can cause trauma to this artery
Radial artery
Lateral side of forearm
Smaller of the two terminal branches
Covered by brachioradialis muscle
Forms deep palmer arch
Radial artery in the hand
At wrist winds around to dorsum of hand
Through anatomical snuff box
Pierces first dorsal interosseous muscle
Ulnar artery
Medial side of forearm
Covered by flexor carpi ulnaris muscle
Deep branch
- common interosseous artery
Forms superficial palmar arch
Ulnar artery in the hand
Branch to deep palmar arch
Venous return
Considerably variable
Drains into axillary vein into subclavian vein
Deep veins and superficial veins
Deep veins
Paired veins
Venae comitantes
Superficial veins
Cephalic (lateral forearm)
Basilic (medial forearm)
Drain into axillary vein
Lymphatic drainage
Relatively few lymph nodes in upper limb (deltopectoral node and cubital nodes)
Lymph drains to axillary nodes
Brachial plexus
Nerve supply to the upper limb
Carries motor, sensory and sympathetic axons
Produces mixed nerves
Divided into roots, trunks, divisions and cords
Roots
Ventral primary rami of C5-T1
Motor innervation
Motor axons within each root innervate a different funcitonal group of muscles
Motor innervation of shoulder abduction and adduction
C5
Motor innervation of elbow flexion and extension
C6/C7
Motor innervation of Wrist flexion and extension
C7/C8
Motor innervation of movement of the digits
C8/T1
Trunks
Roots trunks
Trunks pass through scalene triangle
Divisions
Each trunk divides into anterior and posterior divisions
Anterior: axons to flexor compartments
- forms lateral and medial cords
Posterior: axons to extensor compartments
- forms posterior cord
Cords
Under pectoralis minor
Cords name din relation to axillary artery
Lateral cord
Terminates as:
- musculocutaneous nerve
- lateral part of median nerve
Musculocutnaeous nerve
Motor- anterior arm
Sensory- lateral formarm
Medial cord
Terminates as:
- medial part of median nerve
- ulnar nerve
Median nerve
Motor- anterior forearm and lateral hand
Sensory- lateral palm hand, d1,2,3 + half d4
Ulnar nerve
Motor- medial side anterior forearm and hand
Sensory- medial hand _ half d4 and d5
Posterior cord
Terminates as:
- radial nerve
- axillary nerve
Radial nerve
Motor- posterior arm and posterior forearm
Sensory- posterior arm and posterior forearm and lateral dorsum hand
Axillary nerve
Motor- deltoid and teres minor
Sensory- badge area of arm
Upper limb dermatones
Individual area of skin innervated by a single spinal nerve
Established during development
Lots of overlap/ variation
Cutaneous innervation by terminal branches
Map looks different to dermatome map
Terminal branches contain axons from multiple spinal nerve
