What is the function of left subclavian artery?

The left subclavian artery supplies the left arm and head, as well as some of the thoracic organs.

Arising from the arch of the aorta, just past the origin of the left common carotid artery, the left subclavian artery travels laterally. On the left side of the body, the aortic branches originate somewhat posteriorly compared to the right side, and the left subclavian artery crosses posterior to the left common carotid artery. Next, it ascends into the root of the neck. There, the left subclavian becomes the left axillary artery, supplying the upper limb. Along the way, it gives off several branches.

Major Branches of the Left Subclavian Artery

-Vertebral artery

-Internal thoracic artery

-Thyrocervical trunk:

- Inferior thyroid artery

-Suprascapular artery

-Transverse cervical artery

Blood Supply of the Left Arm

The left subclavian artery is responsible for supplying the upper left quadrant of the body, including the left arm and hand, as well as some of the thoracic structures:

Left vertebral artery: travels up into the vertebral foramen of the cervical vertebrae and contributes to the posterior circulation of the brain.

Left internal thoracic artery: courses along the posterior thoracic wall and provides branches to the thymus, mediastinum, pericardium, and diaphragm, as well as the inferior intercostal spaces and the abdominal wall.

Left thyrocervical trunk: branches into several arteries to provide circulation to the thyroid gland, parathyroids, neck muscles, and scapular region.

Left subclavian artery then becomes the left axillary artery and travels through the axilla, where it gives off further branches to supply the shoulder region. Finally, it becomes the brachial artery at the teres major muscle. The brachial artery, along with its branches—the radial and ulnar arteries—supply the lower arm, wrist, and hand.

Clinical Significance

Aortic arch abnormalities can give rise to problems with blood flow in the left subclavian artery. Most commonly, this occurs with a condition known as aortic coarctation, in which the aorta has a characteristic narrowing just distal to the origin of the left subclavian artery. As a consequence, there is reduced blood supply to the left upper limb, while other branches experience higher pressure. Coarctation of the aorta is usually corrected using surgical intervention in childhood.