What is vein in your neck called?

Veins carry deoxygenated blood from organs, muscles, and other structures back to the heart. They typically have a lower blood pressure than arteries.

While their walls are thinner, veins are usually larger in diameter than arteries and hold about 80% of the body’s total blood, whereas arteries typically only circulate 20% of the blood.

The walls of the internal jugular vein consist of three layers:

The internal jugular vein has a dilated portion at its beginning, called the superior bulb, and another dilated portion at its end, called the inferior bulb, that connect with other veins.

The internal jugular vein also contains the internal jugular vein valve near its end to promote blood flow in one direction toward the heart and prevent backflow toward the brain.

There is an internal jugular vein on both the right and left sides of the neck that originates from an opening on each side of the skull called the jugular foramen. The internal jugular vein dilates at its origin to form the superior bulb of the internal jugular vein, and is a direct continuation of the sigmoid sinus that drains blood from the brain.

The internal jugular vein runs vertically down each side of the neck behind the sternocleidomastoid muscle within the carotid sheath, a tube of connective tissue that runs from the base of the skull to the first rib. The carotid sheath surrounds the internal jugular vein, common carotid artery, and vagus nerve on each side of the neck. The left jugular vein is generally smaller than the right jugular vein.

The end of the internal jugular vein dilates to form the inferior bulb of the internal jugular vein, which contains the internal jugular vein valve. The internal jugular vein comes together with its smaller counterpart, the external jugular vein, and the subclavian vein to form the right and left brachiocephalic, or innominate, veins positioned behind the area where the clavicle meets the sternum. 

The brachiocephalic veins join together to form the superior vena cava, a large vein that directly drains all the deoxygenated blood from circulation of the head, neck, and arms into the right atrium of the heart to be pumped to the lungs to become oxygenated again.

The internal jugular vein is the largest vein in the neck and is the main source of venous drainage, or blood flow, down from the brain, returning deoxygenated blood back from the head and neck to the heart, where it will be pumped to the lungs to become oxygenated again.

The internal jugular vein also serves as the main channel to drain blood from the face and neck via the inferior petrosal sinus, facial vein, lingual vein, pharyngeal vein, and superior and middle thyroid veins that empty into it.

Evaluating the pulse via the internal jugular vein, called the jugular venous pulse, is a useful indicator for indirectly assessing central venous pressure, a measurement used to diagnose many heart conditions. Jugular venous pressure results from the expansion and contraction of the internal jugular vein that occurs with pressure changes in the right atrium of the heart.

The internal jugular vein contains the internal jugular vein valve located near the vein’s end where it connects to the brachiocephalic vein. The internal jugular vein valve prevents backflow of blood from going back into circulation in the brain.

With a strong Valsalva maneuver (taking a large breath and holding it in), the internal jugular vein valves can malfunction due to the increased pressure. This can subsequently increase the blood pressure in the head as the blood backflows into the brain.

When there is a reduction in blood flow through the internal jugular veins, commonly observed in patients with head injury, cerebral hemorrhage, brain tumors, and hydrocephalus, blood can also backflow into the brain. This causes the cerebral blood volume of the brain to increase and results in increased intracranial pressure. If left untreated, increased intracranial pressure can cause serious brain damage.

Internal jugular vein blood flow can also be disrupted from compression caused by an enlarged thyroid gland, tumors, or abnormalities with the surrounding blood vessels and valves.

Conditions involving the internal jugular vein affect proper blood flow down from the head and neck, and can cause serious complications with backflow of blood and increased intracranial pressure in the brain.

Complications affecting the internal jugular vein include:

The internal jugular vein is a paired venous structure that collects blood from the brain, superficial regions of the face, and neck, and delivers it to the right atrium. The internal jugular vein is a run-off of the sigmoid sinus.