Superior vena cava

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Superior vena cava
Gray505.png
The superior vena cava drains from the left and right brachiocephalic veins into the right atrium
Details
Precursorcommon cardinal veins
Drains fromleft and right brachiocephalic veins
Sourcebrachiocephalic vein, azygos vein
Drains toRight atrium
Identifiers
Latinvena cava superior, vena maxima
MeSHD014683
TAA12.3.03.001
FMA4720
Anatomical terminology

The superior vena cava (SVC) is the superior of the two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart. It is a large-diameter (24 mm) short length vein that receives venous return from the upper half of the body, above the diaphragm. Venous return from the lower half, below the diaphragm, flows through the inferior vena cava. The SVC is located in the anterior right superior mediastinum.[1] It is the typical site of central venous access via a central venous catheter or a peripherally inserted central catheter. Mentions of "the cava" without further specification usually refer to the SVC.[citation needed]

Structure[edit]

The superior vena cava is formed by the left and right brachiocephalic or innominate veins, which receive blood from the upper limbs, eyes and neck, behind the lower border of the first right costal cartilage. It passes vertically downwards behind first intercostal space and receives azygos vein just before it pierces the fibrous pericardium opposite right second costal cartilage and its lower part is intrapericardial. And then, it ends in the upper and posterior part of the sinus venarum of the right atrium, at the upper right front portion of the heart. It is also known as the cranial vena cava in other animals. No valve divides the superior vena cava from the right atrium.

Clinical significance[edit]

Superior vena cava obstruction refers to a partial or complete obstruction of the superior vena cava, typically in the context of cancer such as a cancer of the lung, metastatic cancer, or lymphoma. Obstruction can lead to enlarged veins in the head and neck, and may also cause breathlessness, cough, chest pain, and difficulty swallowing. Pemberton's sign may be positive. Tumours causing obstruction may be treated with chemotherapy and/or radiotherapy to reduce their effects, and corticosteroids may also be given.[2]

In tricuspid valve regurgitation, these pulsations are very strong.[clarification needed]

No valve divides the superior vena cava from the right atrium. As a result, the (right) atrial and (right) ventricular contractions are conducted up into the internal jugular vein and, through the sternocleidomastoid muscle, can be seen as the jugular venous pressure.

Additional images[edit]

See also[edit]

References[edit]

  1. ^ "General Practice Notebook". www.gpnotebook.co.uk. Retrieved April 6, 2018.
  2. ^ Britton, the editors Nicki R. Colledge, Brian R. Walker, Stuart H. Ralston ; illustrated by Robert (2010). Davidson's principles and practice of medicine (21st ed.). Edinburgh: Churchill Livingstone/Elsevier. p. 268. ISBN 978-0-7020-3085-7.