Internal jugular vv

The internal jugular vv. (left and right) are the continuations of the sigmoid sinuses, which are inside the skull and drain venous blood from the brain.  The sigmoid sinuses pass through the jugular foramen, and once outside the skull are the internal jugular vv.  In the neck they travel within the carotid sheath with the carotid a. and the vagus n. (CN X).  The internal jugular v. runs just deep to the sternocleidomastoid m., which as been reflected on the left side of the neck to illustrate the vein.