Accessory hemiazygos vein

Vein: Accessory hemiazygos vein
Diagram showing completion of development of the parietal veins. (Accessory hemiazygos vein visible at center-left.)
The venæ cavæ and azygos veins, with their tributaries.
Latin	vena hemiazygos accessoria
Gray's	subject #172 664
Drains to	hemiazygos vein, azygos vein
Dorlands / Elsevier	v_05/12850481

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

The accessory hemiazygos vein (vena azygos minor superior) is a vein on the left side of the vertebral column that generally drains the fifth through eighth intercostal spaces on the left side of the body.

Structure

The accessory hemiazygos vein varies inversely in size with the left superior intercostal vein.

It receives the posterior intercostal veins from the 4th, 5th, 6th, and 7th intercostal spaces between the left superior intercostal vein and highest tributary of the hemiazygos vein; the left bronchial vein sometimes opens into it.

It either crosses the body of the eighth thoracic vertebra to join the azygos vein or ends in the hemiazygos.

When this vein is small, or altogether absent, the left superior intercostal vein may extend as low as the fifth or sixth intercostal space.

See also

• Azygos vein
• Hemiazygos vein

External links

• Accessory+hemiazygos+vein at eMedicine Dictionary
• SUNY Labs 21:12-0200 - "Mediastinum: The Azygos Vein and Posterior Intercostal Veins"

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.