THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -Three branches, the brachiocephalic trunk, left common carotid artery and left subclavian artery usually branch from the aortic arch. These branches may branch from the beginning of the arch or the upper part of the ascending aorta by varying distances between them.

Detailed explanation-2: -Left Subclavian Artery-arises entirely from the left seventh intersegmental artery.

Detailed explanation-3: -The third portion of the subclavian artery runs downward and lateralward from the lateral margin of the scalenus anterior muscle to the outer border of the first rib, where it becomes the axillary artery. This is the most superficial portion of the vessel, and is contained in the subclavian triangle.

Detailed explanation-4: -NORMAL ANATOMY The three main branches of the aortic arch are the brachiocephalic (innominate) artery (dividing into the right subclavian and common carotid arteries), the left common carotid artery, and the left subclavian artery.