Superior vena cava

Superior vena cava

Veins
Details
Precursor common cardinal veins
Source
 brachiocephalic vein, azygos vein
Identifiers
Latin vena cava superior, vena maxima
MeSH A07.231.908.949.815
TA A12.3.03.001
FMA 4720

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), yet short, 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 (CVA) via a central venous catheter or a peripherally inserted central catheter. Mentions of "the cava" without further specification usually refer to the SVC.

Structure of Superior and Inferior Vena Cava

It is formed by the left and right brachiocephalic veins (also referred to as the innominate veins), which also receive blood from the upper limbs, eyes and neck, behind the lower border of the first right costal cartilage. The azygos vein joins it just before it enters 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. 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.

Clinical significance

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.

Additional images

References

  1. ↑ http://www.gpnotebook.co.uk/simplepage.cfm?ID=463077437&linkID=32255&cook=no
  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.

See also

This article uses anatomical terminology; for an overview, see Anatomical terminology.
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