Axilla PDF

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Axilla...

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Axilla Clavipectoral Fascia;  Encloses subclavius and pectoralis minor  Suspensory ligament to fascial floor of axilla Boundaries of the Axilla;  Anterior wall = Pec Major and Minor, Subclavius, fascia  Floor = Skin and into arm  Roof = Rib 1, Clavicle, Scapula  Posterior wall = subscapularis, teres major, latissimus dorsi, long head of triceps brachii  Lateral wall = Humerus  Medial wall = serratus anterior and wall of thorax Contents of Axilla;  Vessels, nerves, lymphatics for upper limb  Short head of biceps and coracobrachialis  Lymph nodes that drain both the upper limb and mammary tissue  Adipose tissue

Axillary Vein;  Basilic vein superficial drains posterio-medial surface hand and forearm, then at the lower margin of Teres Major becomes the axillary vein  Anterior to axillary artery in axilla and becomes subclavian at lat. border rib 1.  Axillary vein joined by brachial veins and cephalic vein (medial brachial vein may join basilic vein)

Axillary Artery;  From subclavian (lat. margin rib1) to brachial (inf. margin teres major)  Ist part proximal to pect. minor = superior thoracic artery  2nd part posterior to pect. minor = thoracoacromial and lateral thoracic arteries  3rd part distal to pect. minor = subscapular, anterior & posterior circumflex humeral arteries  Axillary 1st Part – Lat. Border of 1st rib  Pec minor  Axillary 2nd Part – Deep to Pec Minor  Axillary 3rd Part - Inferolat. Border of Pec Minor  inf. Border of Teres Major

Lymphatics;  Axillary nodes drain upper limb but also drain lateral mammillary tissues, upper back and shoulder, lower neck  Tail of breast tissue into axilla creates pathway  20-30 axillary nodes – 5 groups  Humeral – post. to axillary vein = upper limb  Pectoral – inf. margin pect. minor = thorax and mammary  Subscapular – post. axillary wall = back, shoulder, neck  Central – axillary fat = communicate with other nodes  Apical – sup. margin pect. minor = drain other nodes and mammary tissue Brachial Plexus;  Mixed spinal nerves  Afferent/Efferent  C5-T1  Roots and Trunk; o o o o o o o

C5-C8 in neck and T1 at thoracic inlet Roots receive grey rami communicantes so carry postganglionic sympathetic fibres In posterior triangle of the neck pass between ant. and mid scalene muscles Superior trunk = C5 & C6 Middle trunk = C7 Inferior trunk = C8 & T1 Pass over rib 1 and enter the axilla

 Branches of Root and Trunks; o o o o

C5 root to phrenic nerve (diaphragm), dorsal scapular nerve (rhomboid major and minor muscles) C5-7 roots to long thoracic nerve (serratus anterior muscle) ONLY superior trunk C5, 6 to suprascapular nerve (infraspinatus and supraspinatus muscles) and nerve to subclavius (subclavius muscle)

 Divisions; o o o o

Each trunk divides into an anterior and posterior division 3 anterior divisions ultimate pathway for fibres associated with anterior compartments of the arm and forearm 3 posterior divisions ultimate pathway for nerves associated with posterior compartments of the arm and forearm No peripheral nerves direct from divisions

 Cords; o o

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Named by relation to the axillary artery Lateral = unites anterior divisions of upper and middle trunks therefore C5-7 fibres present, also origin of lateral pectoral nerve Posterior = unites all posterior divisions of the trunks therefore C5-T1 fibres present, also origins of subscapular and thoracodorsal nerves Medial = continuation of anterior division of inferior trunk therefore C8-T1 fibres present, also origins of medial pectoral and cutaneous nerves

 Terminal Nerve Branches; o o o

Lateral cord = (lateral pectoral), musculocutaneous nerve, lateral root of median nerve Posterior cord = (subscapular nerves, thoracodorsal), axillary, radial nerve Medial cord = (medial pectoral, medial cutaneous arm & forearm), ulnar nerve, medial root of median nerve

 Musculocutaneous – C5,6,7  Median – passes through cubital fossa;  Axillary – passes post. To surgical neck of humerus  Radial – Post. Compartment triceps – post. To Humerus  Ulnar - C...