Internal jugular vein
Vena jugularis interna
Also known as: IJV
The internal jugular vein is the main vein draining the brain, face and neck. It begins at the jugular foramen, continuing the sigmoid sinus, runs down in the carotid sheath and joins the subclavian vein behind the sternal end of the clavicle to form the brachiocephalic vein.
Overview
The vein begins at the jugular foramen with a dilatation called the superior bulb. It runs down the neck inside the carotid sheath, at first behind the internal carotid artery and then lateral to the common carotid. The vagus nerve lies behind and between the vessels. The deep cervical lymph nodes run along the vein.
Just above its end it widens into the inferior bulb, which contains a two-cusped valve. Behind the sternal end of the clavicle it joins the subclavian vein to form the brachiocephalic vein. The angle between the two veins is called the venous angle. The thoracic duct drains into it on the left and the right lymphatic duct on the right.
The right internal jugular vein runs in an almost straight line to the SVC and right atrium. This makes it the preferred vein for central venous catheters and for watching the jugular venous pulse.
Anatomy
- Tributaries
The inferior petrosal sinus, and the facial, lingual, pharyngeal, superior thyroid and middle thyroid veins. The occipital vein drains into it occasionally.
- Relations
In front: sternocleidomastoid. Medially: the internal and common carotid arteries, with the vagus nerve behind and between. Behind: the transverse processes of the cervical vertebrae, the cervical plexus and the sympathetic trunk. The anterior scalene muscle and the phrenic nerve lie behind its lower part. The deep cervical lymph nodes lie along it.
Function
- Drains the brain (through the dural sinuses), the face and the neck.
- Gives a window onto right atrial pressure: the jugular venous pressure (JVP).
Clinical significance
Jugular venous pressure
The JVP is the vertical height of the pulsation in the internal jugular vein above the sternal angle, measured with the patient reclining at 45°. Normally it is no more than 3–4 cm. Its waveform has an a wave (atrial contraction), a c wave, an x descent, a v wave (atrial filling) and a y descent (tricuspid valve opening).
Unlike the carotid pulse, the JVP cannot be felt, has two peaks per heartbeat, can be obliterated by gentle pressure, falls on inspiration and rises when the abdomen is pressed (hepatojugular reflux). It is raised in right heart failure, fluid overload, tamponade and SVC obstruction. In SVC obstruction it does not pulsate.
Central venous cannulation
Under ultrasound guidance, the right internal jugular vein is approached near the apex of the triangle between the two heads of sternocleidomastoid. Complications include puncture of the carotid artery, pneumothorax and air embolism. Air embolism is prevented by tilting the patient head-down during insertion.
Lemierre syndrome
Lemierre syndrome is a septic thrombophlebitis of the internal jugular vein that follows a sore throat, usually caused by Fusobacterium necrophorum. Infected clots break off and travel to the lungs (septic emboli).
Compiled from standard anatomy and physiology references — see the Cardiovascular System sources. For education only; not medical advice.