Where does the subclavian vein end and the brachiocephalic vein begin?

From the Guidelines

The subclavian vein ends and the brachiocephalic vein begins at the junction where the subclavian vein meets the internal jugular vein, specifically at the medial border of the anterior scalene muscle near the sternoclavicular joint. This junction is sometimes referred to as the venous angle. At this point, the subclavian vein, which collects blood from the upper limb and travels along the inferior surface of the clavicle, joins with the internal jugular vein, which drains blood from the head and neck. Once these two vessels merge, the resulting vessel becomes the brachiocephalic vein (also called the innominate vein). This anatomical transition occurs deep to the clavicle on each side of the body, though the left and right brachiocephalic veins differ in length and course. The right brachiocephalic vein is shorter and more vertical, while the left brachiocephalic vein is longer and crosses the midline of the body. Both brachiocephalic veins ultimately unite to form the superior vena cava, which returns blood to the right atrium of the heart.

Key points to consider:

• The subclavian vein plays a crucial role in collecting blood from the upper limb.
• The internal jugular vein is responsible for draining blood from the head and neck.
• The junction of these two veins forms the brachiocephalic vein, which is a critical vessel in the venous system.
• Understanding the anatomy of these veins is essential for medical procedures, such as central venous catheterization, and for diagnosing and treating conditions related to the venous system 1.

It's worth noting that while the provided evidence does not directly address the question of where the subclavian vein ends and the brachiocephalic vein begins, anatomical knowledge and medical literature consistently support the description provided above 1.

From the Research

Anatomy of the Subclavian and Brachiocephalic Veins

The subclavian vein and the brachiocephalic vein are major blood vessels in the thoracic region.

• The subclavian vein is a continuation of the axillary vein, running from the outer border of the first rib to the medial border of the scalenus anterior muscle.
• The brachiocephalic vein, also known as the innominate vein, is formed by the junction of the subclavian vein and the internal jugular vein.

Junction of the Subclavian and Brachiocephalic Veins

The subclavian vein ends and the brachiocephalic vein begins at their junction, which is located behind the scalenus anterior muscle and in front of the scalenus medius muscle 2.

• This junction is an important anatomical landmark, as it marks the transition from the subclavian vein to the brachiocephalic vein.
• The brachiocephalic vein then continues to merge with the other brachiocephalic vein to form the superior vena cava.

Clinical Significance

Understanding the anatomy of the subclavian and brachiocephalic veins is crucial in various medical procedures, such as central venous catheterization 3, 4.

• The risk of complications, such as vein stenosis or perforation, can be minimized by careful consideration of the anatomical relationships between these veins 5.
• Additionally, knowledge of the valve structure and function in these veins can inform the development of medical devices and procedures 6.