The Axilla OBJECTIVES Identify the walls of the

The Axilla

OBJECTIVES • • • Identify the walls of the axilla and how structures traverse them Study the course and branches of the axillary artery and recognize its important relations. Understand the arterial anastomosis around the scapula & shoulder joint Locate & study the groups of axillary lymph nodes Study the nerves of the upper limb and deduce their root value by understanding the arrangement of the brachial plexus

Surface anatomy

Walls

Apex (cervicoaxillary canal)= inlet

Axillary walls

Anterior wall

Medial wall

Posterior wall

Gaps in the Posterior wall of the axilla

Lateral wall

The Axillary artery 1 -1 Superior thoracic artery 2 -1 Thoracoacromial artery 2 -2 lateral thoracic artery 3 -1 Subscapular artery 3 -2 Ant. circumflex humeral artery 3 -3 Post. circumflex humeral artery 1 2 3

Humeral anastomosis

Anastomosis around the scapula

Important Relations Axillary vein Brachial plexus P major P minor Subscapularis L dorsi T major Biceps Corachobrachialis

The axillary lymph nodes

1 -CENTRAL � 2 -LATERAL � 3 -PECTORAL � 4 -INFRACLAVICULAR � 5 -SUBSCAPULAR �

The Brachial Plexus

Branches from the roots Dorsal scapular (C 5) Ø Long thoracic (C 5, 6, 7) Ø

Branches from the upper trunk Suprascapular (C 5, 6) Ø Nerve to subclavius (C 5, 6) Ø

Branches from the lateral cord Lateral pectoral (C 5, 6, 7) Ø Musculocutaneous (C 5, 6, 7) Ø Lateral root of the median nerve (C 5, 6, 7) Ø

Branches from the medial cord Ø Ø Ø Medial pectoral (C 8, T 1) Medial cutaneous nerve of the arm (C 8, T 1, 2) Medial cutaneous nerve of the forearm (C 8, T 1) Ulnar nerve (C 7, 8, T 1) Medial root of median nerve (C 8, T 1)

Branches from the posterior cord Ø Ø Ø Upper subscapular (C 5, 6) Lower subscapular (C 5, 6) Thoracodorsal (C 6, 7, 8) Axillary (C 5, 6) Radial (C 5 -T 1)

Relation of the brachial plexus to the axillary artery