Right subclavian artery

At a glance

English

Right subclavian artery

Latin (TA2)

Arteria subclavia dextra

System

Artery

Region

Trunk

Side

Single, on the midline

About the right subclavian artery

The right subclavian artery is one of the two terminal branches of the brachiocephalic trunk, which splits behind the right sternoclavicular joint into this vessel and the right common carotid. Because it does not start at the aorta, it is shorter than the left, around 6 cm in adults, and it often reaches a little higher in the root of the neck. Past the first rib's outer edge it is renamed the axillary artery. It carries most of the right arm's blood and also feeds the neck, brain and chest wall.

Scalenus anterior marks out three parts along its course. The first rises upwards and outwards from its origin to the medial border of that muscle, climbing slightly above the inner end of the clavicle. In front, deep to sternocleidomastoid and the strap muscles, the internal jugular and vertebral veins cross it, as do the vagus nerve and its cardiac branches; a sympathetic loop, the ansa subclavia, encircles it. The right recurrent laryngeal nerve hooks round it from below and behind. Behind it lie the sympathetic trunk, longus colli and the first thoracic vertebra, and the cervical pleura and lung apex lie below and behind.

The second part, behind scalenus anterior and in front of scalenus medius, forms the top of the vessel's arch; on the right, scalenus anterior keeps the phrenic nerve off it. The third part, from the lateral edge of the muscle to the first rib, lies in the subclavian triangle just lateral to the back edge of sternocleidomastoid, where it is the easiest part to reach. Here the external jugular vein crosses it, the subclavian vein lies in front and a little below, and the inferior trunk of the brachial plexus lies behind it on the first rib.

Its branches match the left side: the vertebral and internal thoracic arteries, the thyrocervical and costocervical trunks and usually the dorsal scapular artery. In a small number of people it leaves the aortic arch as the last branch and crosses behind the oesophagus, an aberrant right subclavian artery that may press on the gullet and cause difficulty swallowing. Narrowing before the vertebral origin produces subclavian steal; compression at the thoracic outlet and aneurysm also occur.

Course and supply

Arises from

Given off by the brachiocephalic trunk behind the right sternoclavicular joint.

Ends in

Becomes the axillary artery once it passes the lateral edge of the first rib.

Supplies

Supplies the right upper limb, and through its branches part of the brain and spinal cord, the neck, the thyroid region, the shoulder and the chest wall.