The left Subclavian artery
arises directly from the arch of the aorta. The right subclavian artery arises
with the right common carotid artery from the brachiocephalic trunk. The artery
is described in three parts. The first part lies medial to the scalenus anterior,
the second part lies posterior to the muscle, and the third part lies lateral
to the muscle. At the outer border of the first rib the subclavian continues
as the axillary artery.
The subclavian artery can be compressed in the root of the posterior triangle of the neck. Compression against the first rib can stop a catastrophic hemorrhage or reduce the vascular supply to the upper limb.