The internal jugular vein is a paired jugular vein that collects blood from the brain and the superficial parts of the face and

neck The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...

. This vein runs in the carotid sheath with the common carotid artery and vagus nerve. It begins in the posterior compartment of the jugular foramen, at the base of the skull. It is somewhat dilated at its origin, which is called the ''superior bulb''. This vein also has a common trunk into which drains the anterior branch of the retromandibular vein, the facial vein, and the lingual vein. It runs down the side of the neck in a vertical direction, being at one end lateral to the

internal carotid artery The internal carotid artery (Latin: arteria carotis interna) is an artery in the neck which supplies the anterior circulation of the brain. In human anatomy, the internal and external carotids arise from the common carotid arteries, where these b ...

, and then lateral to the common carotid artery, and at the root of the neck, it unites with the

subclavian vein The subclavian vein is a paired large vein, one on either side of the body, that is responsible for draining blood from the upper extremities, allowing this blood to return to the heart. The left subclavian vein plays a key role in the absorption ...

to form the brachiocephalic vein (innominate vein); a little above its termination is a second dilation, the ''inferior bulb''. Above, it 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 nerve descends between and behind the vein and the artery in the same sheath (the carotid 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 a little distance from the common carotid artery, and crosses the first part of the

subclavian artery In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery supplie ...

, while the ''left internal jugular vein'' usually overlaps the common carotid artery. The left vein is generally smaller than the right, and each contains a pair of valves, which exist about 2.5 cm above the termination of the vessel.

Variation

In 9–12% of the Western population, the size, shape or course of the internal jugular vein is abnormal. Variants identified including veins markedly smaller, or not functionally present. The mean diameter is 10 mm, but may range between 5 and 35 mm.

Tributaries

* Inferior petrosal sinus * Pharyngeal vein * Common facial vein * Lingual vein * Superior thyroid vein * Middle thyroid vein * Occipital vein (sometimes)

Clinical relevance

The jugular veins are relatively superficial and not protected by tissues such as bone or

cartilage Cartilage is a resilient and smooth type of connective tissue. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck an ...

. This makes them susceptible to damage. Due to the large volumes of blood that flow through the jugular veins, damage to the jugulars can quickly cause significant blood loss, which can lead to hypovolæmic shock and then death if not treated.

Jugular venous pressure

As there is one pair of valves between the right atrium of the heart and the internal jugular, blood can flow back into the internal jugular when the pressure in the atrium is sufficiently high. This can be seen from the outside, and allows one to estimate the pressure in the atrium. The pulsation seen is called the

jugular venous pressure The jugular venous pressure (JVP, sometimes referred to as ''jugular venous pulse'') is the indirectly observed pressure over the venous system via visualization of the internal jugular vein. It can be useful in the differentiation of different for ...

, or JVP. This is normally viewed with the patient at 45 degrees turning his/her head slightly away from the observer. The JVP can be raised in a number of conditions: * right ventricular failure (

heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, a ...

), * tricuspid stenosis * tricuspid regurgitation * cardiac tamponade The JVP can also be artificially raised by applying pressure to the liver (the hepatojugular reflux). This method is used to locate the JVP and distinguish it from the carotid pulse. Unlike the carotid pulse, the JVP is impalpable.

Catheterization

As the internal jugular is large, central and relatively superficial, it is often used to place central venous lines. Such a line may be inserted for several reasons, such as to accurately measure the central venous pressure or to administer fluids when a line in a peripheral vein would be unsuitable (such as during resuscitation when peripheral veins are hard to locate). Because the internal jugular rarely varies in its location, it is easier to find than other veins. However, sometimes when a line is inserted the jugular is missed and other structures such as the

carotid artery Carotid artery may refer to: * Common carotid artery, often "carotids" or "carotid", an artery on each side of the neck which divides into the external carotid artery and internal carotid artery * External carotid artery, an artery on each side of t ...

, lung or the vagus nerve (CN X) are punctured, and damage is caused to these structures.

Additional images

File:Gray480.png, Diagram showing completion of development of the parietal veins. File:Venenwinkel.png, The venæ cavæ and azygos veins, with their tributaries. File:Gray1174.png, The thyroid gland and its relations.

References

{{Authority control Veins of the head and neck