Axilla Flashcards
What’s the point of the axilla?
Provides a passageway for neurovascular structures that serve the upper limb.
What are the borders of the axilla?
Anterior wall- pec major and minor
Lateral wall- serratus anterior, 4th rib
Posterior wall- subscapularis, scapula
Apex- humerus
What is the content of the axilla?
Axillary artery, axillary vein and lymphatic vessels.
Axillary lymph nodes are embedded in axillary fat.
Brachial plexus.
The neurovascular structures are encased in axillary sheath.
Talk about the axillary artery.
Subclavian artery, axillary and then becomes brachial artery. Axillary artery is divided into 3 parts:
1) in axillary sheath. 1 branch called superior thoracic artery.
2) posterior to pec major. 2 branches, thoracoacromial and lateral thoracic artery.
3) extends from pec minor to teres minor. 3 branches, subscapular artery, anterior and posterior circumflex numeral artery.
Talk about the axillary vein.
Anteriormedial side of axillary artery. 3 parts from distal to proximal. Forms by the union of the brachial vein and the basilic vein.
What are the 5 lymph groups in the axilla?
Pectoral, subscapular, humeral, central and apical.
Describe the drainage of the axillary lymph nodes.
Pectoral, subscapular and humeral drain into the central lymph node (situated deep in pec minor). Then drains from central to apical node. Majority then drains into subclavian lymphatic trunk.
What is the brachial plexus? Give root values.
Network of nerves that supply the upper limb. Originates in neck from C5,6,7,8 and T1.
What are the 5 parts of the brachial plexus, from proximal to distal?
Roots, trunks, divisions, chords, branches.
Name the trunks for each root.
Superior- C5&6
Middle- C7
Inferior- C8 and T1
What does the axillary nerve innervate, both motor and sensory?
Deltoid muscle and sargents patch.
Where does the Musculocutaneous nerve supply, motor and sensory?
Biceps brachii, lateral forearm.
What does the radial nerve innervate, both motor and sensory?
Triceps brachii, posterior forearm and fingers, so extensor muscles.
Where does the median nerve innervate?
Predominantly flexes from elbow down. Supplies flexes in hand, thumb and 2 fingers.
What does the ulnar nerve innervate?
1st and 2nd fingers.
