Subclavian vein anatomy


The subclavian vein is a large, deep, smoky vein that runs along each side of the neck.

Deep veins are those that are located deep in the body to protect the larger veins from injury . The main function of the veins is to transport deoxygenated blood from all parts of the body, returning it to the heart and then to the lungs for reoxygenation.

Both the right and left subclavian veins are located below the clavicle (clavicle). They connect to the jugular veins, one on each side of the neck, to form brachiocephalic veins, sometimes called anonymous veins. Without the veins and arteries that continually circulate throughout the body, a person could not live . / Getty Images


The subclavian vein is an extension of the axillary vein located under the arm. The subclavian vein runs along the medial (middle) side of a muscle called the scalene anterior muscle.

From there, the subclavian vein continues to the outer edge of the first rib, where it then joins the internal jugular vein to form the brachiocephalic vein (also called the unnamed vein). The brachiocephalic vein connects to one of the largest veins in the body, called the superior vena cava, which carries blood directly to the left atrium of the heart.

As each subclavian vein draws blood from the upper extremities to carry blood back to the heart, they connect to smaller veins (such as jugular veins) on each side of the body. These smaller veins are called tributaries. Tributaries are veins that drain deoxygenated blood into a larger vein. The main tributaries of the subclavian vein include:

  • External jugular vein
  • Dorsal scapular vein
  • Anterior jugular veins

The size

The diameter of the subclavian vein is about 2 cm, which is about the size of your little finger .


Each type of blood vessel, including veins, arteries, and capillaries, has a similar structure, but may differ slightly. Each blood vessel is a hollow tube with a lumen (internal open space) through which blood can pass through the vessel. The width of the blood vessel and the vessel wall may differ depending on the type of vessel.

The three layers that make up the structure of the veins include :

  • Inner sheath: the innermost thin layer of a vein, made up of a single layer of endothelial cells.
  • Sheath environment: the middle layer of the veins.
  • Adventitia: the outer layer of the veins, made up of connective tissues and nerves; this is the thickest layer of the vein.


The left subclavian vein and the right subclavian vein arise as an extension of a vein under the arm called the axillary vein; there is an axillary vein that runs from under the arm on each side of the body.

The subclavian veins originate from the outer edge of the first rib .

Both subclavian veins connect to the jugular veins to form a brachiocephalic vein, which connects to the superior vena cava, which returns blood to the heart.

Anatomical variations

A congenital malformation is an abnormality that occurs during fetal development. This is commonly known as a birth defect. Subclavian vein birth defects are not as common as other types of birth defects, but some cases have been reported .


The main function of the subclavian vein is to drain deoxygenated blood from the upper body, including the arms and shoulder areas, and transport it back to the heart. Another important function of the subclavian vein is the accumulation of lymphatic fluid. of the lymphatic system of the internal jugular vein.

Clinical significance

In the clinical setting, the subclavian vein has traditionally been viewed as a site for insertion of a catheter, which is used to deliver intravenous (IV) fluids and / or drugs directly into the bloodstream. It is known as a central venous catheter , sometimes called a central catheter.

Using the subclavian vein to insert the central line has several advantages and disadvantages, including :

Benefits of using the subclavian bone for the central line

  • The subclavian vein has a predictable course compared to other veins such as the jugular vein.
  • The location is cosmetically acceptable.

Disadvantages of using the subclavian bone for the central line

  • There is a high risk of subclavian vein stenosis (abnormal thickening and narrowing of the vein) due to venipuncture.
  • An increased risk of pneumothorax is the accumulation of air between the thin layer of tissue that covers the chest cavity and the lungs.
  • Increased risk of catheter-associated deep vein thrombosis or DVT, which often results in arm swelling and pain, requiring removal of the catheter and / or thrombolytic treatment with anticoagulants.
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