Axilla Flashcards
Apex of axilla
Cervico- axillary canal
Passageway between neck and axilla
Bounded by 1st rib, clavicle, and superior edge of the scapula
Arteries, veins, lymphatics and nerves transverse superior opening to pass to or from arm
Axilla
Pyramidal space inferior to glenohumeral joint and superior to the skin and axillary fascia at the junction of the arm and thorax
Base of axilla
Formed by the concave skin, subcutaneous tissue, and axillary (deep) fascia extending from the arm to the thoracic wall forming the axillary fossa (armpit)
Anterior wall of axilla
Formed by pectoralis major and minor and pectoral and Clavipectoral fascia associated with them
Anterior axillary fold is inferior most part of anterior wall
Posterior wall of axilla
Formed chiefly by scapula and subscapularis on its anterior surface and inferiorly by teres major and latissimus dorsi
Posterior axillary fold is inferior most part of posterior wall that may be grasped
Medial wall of axilla
Formed by thoracic wall and overlying serratus anterior
Lateral wall of axilla
Narrow bony wall formed by intertubercular sulcus of humerus
Axilla contains
Axillary artery and branches, axillary vein and tributaries, nerves of cords and branches of brachial plexus, lymphatic vessels and axillary lymph nodes all embedded in axillary fat
Proximally, neurovascular structures are ensheathed in a sleeve like extension of the cervical prevertebral fascia, the axillary sheath
Axillary artery
Begins at lateral border of 1st rib as continuation of subclavian artery and ends at inferior border of teres major
Passes posterior to pectoralis minor into the arm and becomes the brachial artery when it passes distal to the inferior border of the teres major
First part of axillary artery
Located between lateral border of first rib and medial border of pectoralis minor
It is enclosed in axillary sheath and has one branch: superior thoracic artery
Second part of axillary artery
Posterior to pectoralis minor and has two branches: thoraco acromial artery and lateral thoracic artery, which pass medial and lateral to the muscle, respectively
Third part of axillary artery
Extends from lateral border of pectoralis minor to inferior border of teres major and has three branches
Subscapular artery is largest branch
Opposite origin of this artery: anterior circumflex humeral artery and posterior circumflex humeral artery arise
Axillary vein
Lies initially on the anteromedial side of axillary artery, with its terminal part anteroinferior to the artery
Formed by the union of the accompanying brachial veins and the basilic vein at the inferior border of the teres major
It ends at the lateral border of the first rib where it becomes the subclavian vein
Veins of axilla are more abundant, highly variable, and more likely to anastamose
Compression of axillary artery
Compression of third part against humerus may be necessary with profuse bleeding
If need it at more proximal site, can be compressed at its origin at lateral border of first rib by exerting downward pressure in angle between clavicle and attachment of SCM
Injury to axillary vein
Very easy because large and exposed
Dangerous because bleeding and air emboli