External Jugular Vein
The External Jugular vein
is formed by the posterior auricular and retromandibular veins at the angle
of the mandible. It courses subcutaneously on the surface of the sternocleidomastoid,
and pierces the investing deep fascia as a tributary of the subclavian vein.
The external jugular vein provides superficial access to the central venous system. When venous pressure is within the normal range, the external jugular is either invisible or observable for only a short distance superior to the clavicle. Congestive heart failure (CHF) renders the external jugular vein prominent throughout its course. A venous air embolism, produced by laceration of the external jugular vein and its failure to collapse, fills the right heart with froth and practically stops blood flow through it. Pulsation of the internal jugular vein may be diagnostic of obstruction of the superior vena cava, enlarged supraclavicular nodes, hypertrophy of the right atrium, or increased intrathoracic pressure. Such venous pulsation will be noted before the corresponding carotid pulsation.