The Anatomy of the Subclavian Artery

A large artery that supplies blood to the upper body

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Arteries are large blood vessels that carry oxygenated blood from the heart to the cells, tissues, and organs throughout the body. They can be found in every part of the body (except the hairs, nails, upper layer of the skin, cartilage, and cornea of the eye).

The subclavian artery is a major blood vessel located in the thorax (chest area) that functions to carry oxygen-rich blood from the heart to parts of the upper body, including the:

  • Arms
  • Head
  • Neck
  • Segment of the brain with oxygenated blood
Subclavian Artery Anatomy

Ellen Lindner / Verywell

Anatomy

Branches of the Subclavian Artery

The left and right subclavian arteries are located in the thorax (chest) underneath the clavicles (commonly known as the collarbones). The left subclavian artery receives oxygenated blood from the aortic arch (the top portion of the largest artery in the body that carries blood away from the heart). The right subclavian artery receives blood from the brachiocephalic branch.

The Left Subclavian Artery

  • Branches off directly from the arch of the aorta (as it travels down to supply oxygenated blood to the upper body)
  • Passes between the anterior and middle scalene muscles (located in the neck)
  • Ends at the outer border of the first rib where it becomes the axillary artery, which supplies blood to the axillary (armpit area) region of the body. The axillary artery continues down the arm to become the ulnar and radial arteries (supplying oxygenated blood to the arm).

The Right Subclavian Artery

  • Arises from the brachiocephalic trunk (the second branch to arise from the aorta)
  • Travels posteriorly (behind) the sternoclavicular joint (the area where the clavicle [collarbone] and the sternum [breastbone] come together).
  • Becomes the axillary artery once it passes the first rib. The axillary artery supplies blood to the axillary region of the body; it extends down the arm to become the ulnar and radial arteries (supplying oxygenated blood to the arm).

Structure

There are two types of arteries: Elastic and muscular.

Elastic arteries are large arteries that have the ability to stretch; they contain a high amount of collagen and elastin (more than the muscular arteries are comprised of). These arteries are the largest in the body and they are closest to the heart; they give rise to medium-sized vessels—muscular—arteries. The reason elastic arteries must be more easily able to stretch is because they must be able to manage a relatively constant pressure (inside the vessels) despite the pressure caused by the heart’s continuous pumping action.

Elastic arteries include:

  • The aorta
  • Pulmonary artery
  • Brachiocelphlic trunk
  • Common carotid arteries
  • Vertebral artery
  • Common iliac arteries
  • Femoral artery
  • Subclavian artery

An artery has several layers, including:

  • The intima: The innermost layer That is lined by endothelium—a thin membrane that lines the inside of the blood vessels and is comprised of endothelial cells, which release substances that control relaxation and contraction of blood vessels.
  • The tunica media layer: A thick layer of the blood vessel that contains contractile tissue, which enables the artery to contract; the tunica media layer is comprised of connective tissue, elastic fibers, and smooth muscle cells. This layer allows the artery to endure high pressure that results from the pumping of the heart.
  • The tunica adventitia layer: The tough outer layer of the artery, which is comprised primarily of collagen fibers that act to structurally support the artery. Large arteries—such as the subclavian artery—have a thicker tunica adventitia layer as well as a much thicker tunica media layer (compared to smaller arteries).

Location

The subclavian artery is a major artery that branches off of the aorta. The aorta is the largest artery in the body, which is connected to the heart's left ventricle. The larger trunks—such as the aorta and the subclavian artery—are located in the most protected areas of the body to prevent injury and subsequent disruption of major blood flow. The subclavian artery is found in the chest, under the rib cage, which helps protect the vessel from injury.

Anatomical Variations

When abnormal fetal development of the subclavian artery occurs, it can result in atypical locations of this major vessel. Most commonly, aberrant right subclavian artery occurs, which results in the artery being displaced to an area between the trachea (windpipe) and esophagus (the tube through which food passes, after swallowing). This can cause symptoms such as trouble breathing or swallowing. Discrepancies of the normal branching pattern of the subclavian can also occur as a result of malformation during fetal development.

Function

The primary function of the subclavian artery is to provide oxygen-rich blood to certain areas of the upper body. There are two subclavian arteries, which supply oxygen-rich blood to each side of the body. The subclavian arteries also provide oxygenated blood to the back of the cerebrum (the largest part of the brain), the neck and upper limbs, as well as the superior (upper region) and anterior (front area) of the chest wall.

Clinical Significance

When a person has subclavian artery disease, it increases the risk of having a buildup of plaques in other arteries in the body. Depending on where the blockage occurs, this can lead to serious complications such as a heart attack, chronic (long-term) chest pain or a stroke. When the blockage occurs in the legs it can cause severe cramping, called claudication.

Often, there are no noticeable symptoms of subclavian artery disease. This is because the condition progresses slowly over time. Another reason symptoms may not be apparent at first is that the body has a fail-proof system called collateral circulation. Collateral circulation involves specialized blood vessels that bypass the area where blood flow is blocked. This occurs as the body’s way of protecting against injury from coronary artery disease, stroke, or peripheral artery disease (such as atherosclerosis in the subclavian artery).

Symptoms that may occur as a result of a blockage of the subclavian artery include:

  • Pain or muscle fatigue when the arms are in use in above the head movements
  • Pain or muscle fatigue when performing strenuous arm movements
  • Dizziness with arm activity
  • Feeling as though you may faint
  • Blurred vision, double vision, or partial loss of vision
  • A significant difference (more than 20 mm Hg) in blood pressure or in pulses between both arms
  • A change in color (bluish discoloration) of the fingers in the affected extremity (in severe instances)

When symptoms are noticeable, your healthcare provider should be notified right away; imaging tests may be performed to evaluate the blood flow from the subclavian artery. Other types of diagnostic tests, such as lab, work may also be ordered.

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7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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