Nerve and blood supply UL 22-23.pptx
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Nerve and Blood Supply to the Upper Limb Dr Catherine Hennessy [email protected] Learning Outcomes Describe the arterial supply of the upper limb, the venous and lymphatic drainage of the upper limb Describe the stem artery to the upper limb – the Subclavian artery Explain the importance of th...
Nerve and Blood Supply to the Upper Limb Dr Catherine Hennessy [email protected] Learning Outcomes Describe the arterial supply of the upper limb, the venous and lymphatic drainage of the upper limb Describe the stem artery to the upper limb – the Subclavian artery Explain the importance of the scapular anastomosis Explain the arterial supply of the arm and forearm Explain the venous return of the upper limbs Explain the upper limb lymphatic drainage Describe the organisation of the brachial plexus Blood supply to the upper limb Stem Artery - Subclavian Subclavian artery supplies the upper limb Right common carotid artery Right subclavian artery Left common carotid artery Left subclavian artery Brachiocephalic trunk RIGHT - from brachiocephalic trunk LEFT - from arch of the aorta Subclavian Artery Passes through the scalene triangle • • • Superior to first rib Anterior to Middle Scalene Posterior to Anterior Scalene First rib Divided into 3 parts by Anterior Scalene: 1st Medial to muscle 2nd Behind muscle 3rd Lateral to muscle Subclavian Artery Dorsal scapular artery (from 2nd or 3rd part) Contributes to scapular anastomosis Thyrocervical trunk (to thyroid, cervical, scapula) Contributes to scapular anastomosis 3rd 2nd 1st Vertebral artery Brachiocephalic trunk RHS Subclavian Artery Ends at it crosses lateral border of first rib Subclavian artery Becomes axillary artery First rib Axillary artery Axillary Artery Divided into three parts by pectoralis minor: 1st Medial to muscle 2nd Behind muscle 3rd Lateral to muscle Closely associated with the brachial plexus Ends at lower border of teres major Becomes brachial artery Axillary Artery 1st 2nd 3rd Subscapular artery (To scapular anastomosis) Surgical neck of humerus Risk of fracture can lead to trauma of Ant/post circumflex humeral artery (To neck/shaft of humerus) Brachial Artery Superficial throughout arm Supplies flexors o rs x e l F Brachial artery M L ors s n e t Ex Large branch - Profunda brachii artery Supplies extensors Contributes to anastomosis around elbow Radial artery Divides in cubital fossa into: Radial and Ulnar arteries Ulnar artery Profunda Brachii in Spiral/radial groove Deep Brachial / Profunda Brachii Artery Accompanies radial nerve in spiral groove Quadrangular space Posterior circumflex humeral artery Profunda brachii artery Position of the Spiral/radial groove Radial nerve Clinical: Fracture to humerus – trauma to profunda brachii artery Radial Artery Lateral side of forearm Smaller of the two terminal branches Covered by brachioradialis muscle Forms deep palmar arch Brachial artery Radial artery Radial Artery in the Hand At wrist winds around to dorsum of hand Radial artery First dorsal interosseous muscle Deep palmar arch (below flexor tendons) Through anatomical snuff box Pierces first dorsal interosseous muscle Palmar surface Ulnar Artery Medial side of forearm Brachial artery Covered by flexor carpi ulnaris muscle Deep branch aka Common interosseous artery Flexor carpi ulnaris (removed) Forms superficial palmar arch Ulnar artery Ulnar Artery in the Hand Ulnar artery Branch to deep palmar arch Superficial palmar arch (above flexor tendons) Palmar digital arteries Venous Return Considerably variable Drains into axillary vein into subclavian vein Deep veins Accompany the arteries (same names) Paired veins Venae comitantes Superficial veins Cephalic located on the lateral forearm Basilic located on the forearm Originate from dorsal venous arch Superficial Veins Cephalic and basilic veins drain into the axillary vein Anterior Posterior Median cubital vein Basilic vein Deltopectoral groove Cephalic vein Cephalic vein Basilic vein Dorsal venous arch Basilic vein Lymphatic Drainage Relatively few lymph nodes in upper limb Deltopectoral node (Cephalic vein) Axillary nodes (Axillary vein) Cubital nodes (Basilic vein) Nerve supply to the upper limb Brachial Plexus Nerve supply to the upper limb Carries motor, sensory and sympathetic axons Produces mixed nerves i.e. contains axons from multiple spinal nerves Important to supply large muscle groups Brachial Plexus Overview Divided into roots, trunks, divisions, cords and branches (mixed nerves) Roots Trunks Divisions Cords Terminal branches Roots Roots are ventral primary rami of C5 – T1 Dorsal scapular nerve (to the rhomboids and levator scapulae) Roots C5 C6 C7 C8 T1 Long thoracic nerve (to serratus anterior) Motor Innervation Motor axons within each root innervate a different functional group of muscles (myotomes) C5 Shoulder abductor (Deltoid) Roots C6 Elbow flexors (Biceps) C5 C6 C7 Elbow extensors (Triceps) Wrist flexors/extensors C7 C8 C8 Digit flexors/extensors T1 Digit ab/adductors T1 Trunks Roots form trunks Trunks pass through scalene triangle with the subclavian artery Suprascapular nerve Roots Trunks ior r e Sup dle d i M or i r e Inf 1st Rib C5 C6 C7 C8 T1 Divisions Each trunk divides into anterior and posterior divisions Anterior: Axons to flexor compartments [Forms lateral and medial cords] Divisions Posterior: Axons to extensor compartments [Forms posterior cord] Anterior division Posterior division Roots Trunks ior r e Sup dle d i M or i r e Inf C5 C6 C7 C8 T1 Cords Under pectoralis minor Cords named in relation to axillary artery Roots Trunks Divisions Cords Axillary artery al r te a L ior r te s Po M ial d e ior r e Sup dle d i M or i r e Inf C5 C6 C7 C8 T1 Cords of the Brachial Plexus Lateral Cord Terminates as: • Musculocutaneous nerve • Lateral part of median nerve Lateral cord Musculocutaneous nerve Median nerve Medial cord Musculocutaneous Nerve Biceps brachii muscle Coracobrachialis muscle Motor – Anterior arm Sensory – Lateral forearm Brachialis muscle Lateral cutaneous nerve to forearm Medial Cord Terminates as: • Medial part of median nerve • Ulnar nerve Lateral cord Median nerve Medial cord Ulnar nerve Median Nerve Motor – Anterior forearm and lateral hand Sensory – Lateral palm hand and lateral 3 and ½ digits (d1, 2, 3 + half d4) Carpal tunnel Ulnar Nerve Cubital tunnel Flexor carpi ulnaris muscle Motor – Medial side anterior forearm and hand Sensory – Medial hand + medial 1 and ½ digits (half d4 + d5) Posterior Cord Terminates as: • Radial nerve • Axillary nerve Posterior cord Axillary nerve Radial nerve Radial Nerve Deep branch (motor) Superficial branch (sensory) Supinator muscle Radial nerve Spiral groove of humerus Brachioradialis muscle Triceps Motor – posterior arm and posterior forearm Sensory – posterior arm and posterior forearm + lateral dorsum hand Axillary Nerve Axillary nerve Quadrangular space Motor – deltoid and teres minor Sensory – badge area of arm Terminal Branches Musculocutaneous nerve Axillary nerve Median nerve Radial nerve Ulnar nerve Upper Limb Dermatomes “An individual area of skin innervated by a single spinal nerve” Established during development Lots of overlap/variation Clinical: Altered sensation in the region of a dermatome indicates damage to specific spinal nerve of spinal cord segment (i.e. proximal nerve injury) Cutaneous Innervation by Terminal Branches Map looks different to dermatome map Terminal branches contain axons from multiple spinal nerves cervical plexus axillary (badge area) radial Dermatome map musculocutaneous From medial cord medial cutaneous ulnar median Clinical: Altered sensation in one of the above areas indicates damage to a more distal nerve segment (i.e. distal nerve injury)
