WINDSOR UNIVERSITY SCHOOL OF MEDICINE St.Kitts DEPARTMENT OF ANATOMY UPPER LIMB AXILLA Dr. SREEKANTH THOTA

AXILLA The axilla is the gateway to the upper limb, providing an area of transition between the neck and the arm. Axilla is an irregularly shaped pyramidal space with: 1.Four sides; 2.An inlet 3.Floor (base)

Borders of the Axilla:

Contents: 1. Axillary artery and its branches 2.Axillary vein and its tributaries 3.Axillary lymph nodes 4.Brachial plexus The contents are embedded in fat and ensheathed in the axillary sheath

Axillary artery The subclavian artery in the neck becomes the axillary artery at the lateral margin of rib I and passes through the axilla, becoming the brachial artery at the inferior margin of the teres major muscle.

Branches of the axillary artery The axillary artery is separated into three parts by the pectoralis minor muscle, which crosses anteriorly to the vessel. First part is proximal to pectoralis minor Second part is posterior to pectoralis minor Third part is distal to pectoralis min.

Branches of the axillary artery

six branches arise from the axillary artery: One branch, the superior thoracic artery, originates from the first part. Two branches, the thoraco-acromial artery and the lateral thoracic artery, originate from the second part; Three branches, the subscapular artery, the anterior circumflex humeral artery, and the posterior circumflex humeral artery, originate from the third part.

Arterial Anastomoses around the Scapula Collateral circulation: Subclavian artery-----Suprascapular artery--------circumflex scapular artery----subscapular artery----axillary artery

Axillary vein The axillary vein begins at the lower margin of the teres major muscle and is the continuation of the basilic vein. The axillary vein passes through the axilla medial and anterior to the axillary artery and becomes the subclavian vein. Tributaries of the axillary vein generally follow the branches of the axillary artery. Other tributaries include brachial veins that follow the brachial artery, and the cephalic vein.

Axillary vein

Lymphatics All lymphatics from the upper limb drain into lymph nodes in the axilla. The 20-30 axillary nodes are generally divided into five groups on the basis of location 1. humeral (lateral) nodes 2. pectoral (anterior) nodes 3. subscapular (posterior) nodes 4. central nodes 5. apical nodes

Lymph nodes in the axilla