The internal jugular vein is a vein in the head that extends from the base of the skull to the angle of the vein. At the jugular foramen, bleeding from the vein can damage cranial nerves IX through XI, each leading to characteristic syndromes.
What is the internal jugular vein?
The internal jugular vein is one of the blood vessels of the head and neck and represents a component of the systemic circulation. Blood flows through it out of the head and toward the heart, where the vital organ receives the blood and then pumps it into the pulmonary circulation. In the pulmonary circulation, oxygen molecules can attach to the red blood cells (erythrocytes), while carbon dioxide diffuses out of the blood. The internal jugular vein contains oxygen-depleted blood that collects in increasingly larger blood vessels starting in the brain. The venous counterpart to the internal jugular vein is the external jugular vein or vena jugularis externa. It runs closer to the surface of the body than the internal jugular vein and also extends from the head down the neck to the angle of the vein or joins the internal jugular vein. However, compared with the internal jugular vein, the diameter of the external jugular vein is much smaller.
Anatomy and structure
The internal jugular vein begins at the zygomatic vein hole (foramen jugulare), which is located at the base of the skull. Anatomy also refers to the passage as the jugular hole. The blood vessel is located here next to the glossopharyngeal nerve, the vagus nerve and the accessorius nerve. The three nerves supply nerve signals to wide areas in the head and neck. At the zygomatic vein hole, the sigmoid sinus flows into the internal jugular vein, which drains blood from the brain. In addition, the first distention of the internal jugular vein is located here in the form of the bulbus superior venae jugularis internae. This is followed by the internal jugular vein of the internal carotid artery to its origin at the common carotid artery. From there, the internal jugular vein accompanies the carotid artery through the neck and eventually joins the angle of the vein in the chest. At this point, the internal jugular vein meets the subclavian vein and has a second distention, the bulbus inferior venae jugularis internae. The internal jugular vein flows under the sternoclavicular joint (articulatio sternoclavicularis) in the brachiocephalic vein and ends there.
Function and Tasks
The function of the internal jugular vein is to receive deoxygenated blood and pass it on to the venous angle. There, the blood first flows into the brachiocephalic vein and on to the superior vena cava, which finally conveys it to the right atrium of the heart (atrium cordis). The heart then pumps the blood into the small circulation or pulmonary circulation. Prior to this, the internal jugular vein receives several inflows. Among the most important are the fine inlets from the head, which already join the vein at the jugular foramen. They drain blood from the brain, which serves to supply the central nervous system. Correct drainage is important to avoid disruption of blood flow. From the face, oxygen-depleted blood flows in the facial vein to the internal jugular vein. Its blood, in an oxygenated state, previously supplied numerous muscles of the face as well as connective tissue, nerves and other tissues. The venae pharyngeales also belong to the tributaries of the internal jugular vein and drain blood from the pharyngeal plexus. In addition to the external jugular vein, the lingual and meningeal veins and a thyroid vein also use the internal jugular vein as a drain. The same is true for the sternocleidomastoid vein, whose blood originates from the head nodule (sternocleidomastoid muscle).
Diseases
Various complications such as inflammation are possible with jugular vein thrombosis. Hemorrhage of the internal jugular vein at the jugular foramen can damage the ninth to eleventh cranial nerves. Other injuries, tumors, inflammation, and atrophy also represent possible lesions in this region and result in characteristic clinical pictures. Avellis (Longhi) syndrome results from a lesion of the medulla oblongata and leads to neurologic symptoms due to damage to the glossopharyngeal and vagus nerves. The palate, pharynx and vocal cord are paralyzed on the side where the lesion is located.In addition, hemiparesis of the opposite (contralateral) side occurs. Furthermore, some individuals suffering from Avellis syndrome experience only diminished pain and temperature (hemihypesthesia). Another syndrome that results from injury, hemorrhage, tumors, and other damage to the jugular foramen is Jackson or Schmidt syndrome. Hypoglossal paralysis also occurs in this case – tongue paralysis is the most characteristic feature. In contrast, Sicard’s syndrome presents in the form of nerve pain (neuralgia). Vernet’s syndrome is accompanied by spastic paralysis and also manifests itself in other neurological symptoms such as tasting disorders, which are due to the failure of the responsible cranial nerves. Villaret’s syndrome is also due to a lesion of the medulla oblongata at the foramen jugulare. This clinical picture paralyzes the facial nerve, the glossopharyngeal nerve, the vagus nerve and the accessorius nerve on one side of the body. In addition, medicine makes partial use of the internal jugular vein to insert a central venous catheter (CVC) into it. To do this, a physician advances the thin tube inside the vein, all the way to the heart. Through the CVC, drugs such as cardiac agents, chemotherapeutic agents or electrolyte solutions can be administered directly to the heart. In addition, the CVC is suitable for determining the central venous pressure. When examining the internal jugular vein, physicians use an ultrasound machine or other imaging techniques.
