The internal jugular vein is a paired jugular vein that collects blood from the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

and the superficial parts of the face and

neck The neck is the part of the body in many vertebrates that connects the head to the torso. It supports the weight of the head and protects the nerves that transmit sensory and motor information between the brain and the rest of the body. Addition ...

. This vein runs in the

carotid sheath The carotid sheath is a condensation of the deep cervical fascia enveloping multiple vital neurovascular structures of the neck, including the common and internal carotid arteries, the internal jugular vein, the vagus nerve (CN X), and ansa c ...

with the

common carotid artery In anatomy, the left and right common carotid arteries (carotids) () are artery, arteries that supply the head and neck with oxygenated blood; they divide in the neck to form the external carotid artery, external and internal carotid artery, inte ...

and

vagus nerve The vagus nerve, also known as the tenth cranial nerve (CN X), plays a crucial role in the autonomic nervous system, which is responsible for regulating involuntary functions within the human body. This nerve carries both sensory and motor fibe ...

. 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 is an artery in the neck which supplies the anterior cerebral artery, anterior and middle cerebral artery, middle cerebral circulation. In human anatomy, the internal and external carotid artery, external carotid ari ...

, and then lateral to the

, and at the root of the neck, it unites with the subclavian vein 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

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

descends between and behind the vein and the

artery An artery () is a blood vessel in humans and most other animals that takes oxygenated blood away from the heart in the systemic circulation to one or more parts of the body. Exceptions that carry deoxygenated blood are the pulmonary arteries in ...

in the same sheath (the

), 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

, and crosses the first part of the subclavian artery, 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 A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

cartilage Cartilage is a resilient and smooth type of connective tissue. Semi-transparent and non-porous, it is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints ...

. 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, 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 caused by an impairment in the heart's ability to Cardiac cycle, fill with and pump blood. Although symptoms vary based on which side of the heart is affected, HF ...

), * 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, lung or the

(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 Human head and neck Cardiovascular system Otorhinolaryngology