Main Article Content
Internal jugular veins (IJVs) are the largest veins in the neck and are considered the primary cerebral venous drain for the intracranial blood in supine position. Any reduction in their flow could potentially results an increase in cerebral blood volume and intracranial pressure (ICP). The right internal jugular vein communicates with the right atrium via the superior vena cava, in which a functional valve is located at the union of the internal jugular vein and the superior vena cava. The atrium aspiration is the main mechanism governing the rhythmic leaflets movement of internal jugular vein valve synchronizing with the cardiac cycle. Cardiac contractions and intrathoracic pressure changes are reflecting in Doppler spectrum of the internal jugular vein. The evaluation of the jugular venous pulse provides valuable information about cardiac hemodynamics and cardiac filling pressures. The normal jugular venous pulse wave consists of three positive waves, a, c, and v, and two negative waves, x and y. A normal jugular vein gradually reduces its longitudinal diameter, as described in anatomy books; it is possible to segment IJV into three different segments J3 to J1, as it proposed in ultrasound US studies and CT scan. In this review, the morphology and methodology of the cerebral venous drainage through IJV are presented.