B) Arteries Of The Upper Limb

Arteries of the Neck

The main artery of the arm is the subclavian artery. Its course varies between right and left. The remaining vessels of the arm have similar courses.

Right Subclavian Artery

The right subclavian artery is the principal artery of the right upper limb. It arises from the division of the brachiocephalic artery, the first branch of the arch of aorta, posterior to the sternoclavicular joint. It travels laterally in an arch, ascending to just above the clavicle before descending to enter the axilla upon the outer border of the first rib. The anterior scalene muscle overlies the central part of the artery, dividing it into three parts.
The first part of the right subclavian artery gives off several branches, of which only the thyrocervical trunk contributes to the supply of the upper arm and clavicular regions. The thyrocervical trunk ascends briefly before dividing into numerous smaller branches, of which the transverse cervical and suprascapular arteries direct blood to the posterior parts of the scapula and clavicular region.
The second part of the right subclavian artery gives rise to the costocervical trunk, branches of which supply muscles associated with the first rib and clavicle. The third part of the right subclavian artery has no branches.
As it passes the outer border of the first rib and enters the axilla, the artery becomes the axillary artery.

Left Subclavian Artery

The left subclavian artery is the final branch of the arch of aorta. It passes superiorly, posterior to the left common carotid and medial to the upper lobe of the lung, before curving laterally and eventually inferiorly to pass superior to the first rib. Like the right subclavian, it has three parts.
The first part of the left subclavian is substantially longer than the right, given the different origin of the vessel. This part is posterior to the left common carotid and left brachiocephalic vein. The trachea, oesophagus, thoracic duct and recurrent laryngeal nerve lie medial.
The second and third parts are very similar to the right subclavian artery.

Arteries of the Axilla

The main artery of the axilla is the axillary artery.

Axillary artery

The axillary artery begins at the lateral border of the first rib as the continuation of the subclavian artery. Its middle section is covered anteriorly by the pectoralis minor muscle, which divides the artery into three parts.

First Part of the axillary artery

The first, proximal part of the axillary artery lies in the apex of the axilla. The axillary vein is typically medial and slightly anterior; the brachial plexus lies posteriorly. The superior thoracic artery is the only branch of the first part, descending inferiorly along the medial border of pectoralis minor.

Second Part of the axillary artery

The second part lies beneath the pectoralis minor. At this level, the cords of the brachial plexus (medial, lateral, posterior) are related to the vessel as their names would imply. The axillary vein continues its medial and anterior course.
The thoraco-acromial artery is the first branch of the second part. It passes anteriorly, curving above the medial edge of pectoralis minor, before dividing into several named branches which supply the deltoid, pectoral muscles, clavicle and scapula.
The lateral thoracic artery arises just medial to the lateral border of pectoralis minor. It descends along the lateral border of pectoralis minor, supply the muscle and the overlying chest wall. This artery is larger in women as it contributes a significant amount of supply to the mammary glands.

Third part of the axillary artery

The final part of the axillary artery passes inferolaterally through the remaining axilla to end at the inferior border of teres major where it continues as the brachial artery. The cords and terminal branches of the brachial plexus surround the artery. The axillary vein lies medial.There are three branches of the third part:

  • The anterior and posterior circumflex humeral arteries pass around the proximal shaft of the humerus and anastamose on its lateral surface. They supply the proximal parts of the muscles of the arm, including biceps, triceps and coracobrachialis.
  • The subscapular artery descends on the lateral-inferior border of subscapularis to the inferior angle of the scapula. It supplies the muscles of the rotator cuff.

Brachial Artery

Arteries of the Forearm

Radial Artery

Ulnar Artery

Arteries of the Hand

Links