Left internal jugular vein
Vena jugularis interna sinistra
Definition
The left internal jugular vein (LIJV) is a major venous structure that exits the jugular foramen at the skull base and descends through the neck within the carotid sheath to join the left subclavian vein, forming the left brachiocephalic vein at approximately the level of the sternal head of the clavicle. The vein typically courses from a posterior position relative to the internal carotid artery superiorly to a more anterolateral position as it descends caudally.
Traject:
The left internal jugular vein is directly continuous with the transverse sinus, and begins in the posterior compartment of the jugular foramen, at the base of the skull. At its origin it is somewhat dilated, and this dilatation is called the superior bulb.
It runs down the side of the neck in a vertical direction, lying at first lateral to the internal carotid artery, and then lateral to the common carotid, and at the root of the neck unites with the subclavian vein to form the brachiocephalic vein; a little above its termination is a second dilatation, the inferior bulb.
Relations
Above, the internal jugular vein lies upon the Rectus capitis lateralis, behind the internal carotid artery and the nerves passing through the jugular foramen; lower down, the vein and artery lie upon the same plane, the glossopharyngeal and hypoglossal nerves passing forward between them; the vagus descends between and behind the vein and the artery in the same sheath, and the accessory runs obliquely backward, superficial or deep to the vein. At the root of the neck the right internal jugular vein is placed at a little distance from the common carotid artery, and crosses the first part of the subclavian artery, while the left internal jugular vein usually overlaps the common carotid artery.
The internal jugular vein receives in its course different afferent veins:
References
This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. edition of Gray's Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).
