Jugular vein

A jugular vein is one of the veins that drain blood out of the head and neck. Each side has an internal jugular vein, a deep, wide vessel that is the main outflow from the brain, and an external jugular vein, a smaller vessel just under the skin. Small anterior jugular veins drain the front of the neck.

The internal jugular vein begins at the base of the skull, carrying on from the sigmoid sinus, one of the channels that gather blood from the brain, as it leaves through the jugular foramen. It descends in the carotid sheath, a connective tissue sleeve shared with the carotid artery and the vagus nerve, picking up veins from the face, tongue and thyroid. Behind the inner end of the collarbone it merges with the subclavian vein, creating the brachiocephalic vein, which drains into the superior vena cava. The external jugular vein forms just below the ear, drains much of the scalp and outer face, and empties into the subclavian vein.

Because the internal jugular vein links almost directly to the right atrium, the height of its pulse in the neck, the jugular venous pressure, gives a rough bedside estimate of right heart pressure and is often raised in heart failure. It is also a common site for a central venous catheter.