External Jugular Vein Anatomy

External Jugular Vein: Anatomy, Tributaries, Drainage

Write a short note on the external jugular vein.
Answer.

External Jugular Vein Formation The external jugular vein is formed on the sternocleidomastoid muscle below and behind the angle of the mandible by the union of the posterior auricular vein and posterior division of the retromandibular vein. It has two valves – one before its termination and another an inch above the middle of the clavicle.

External Jugular Vein Course It descends obliquely downwards and backwards across the sternocleidomastoid. It pierces the superficial lamina of the investing layer of deep cervical fascia above the clavicle in the region of the subclavian triangle. Here it crosses the third part of the subclavian artery and after piercing a deep lamina of the investing layer of the deep cervical fascia ends in the subclavian vein deep into the clavicle.

External Jugular Vein Tributaries These are

• Anterior jugular vein
• Transverse cervical vein
• Suprascapular vein

External Jugular Vein Applied anatomy

• Air embolism: If the external jugular vein is cut an inch above the clavicle, its lumen is held open because its margins are adhered to the deep fascia. As a result, the air is sucked into the lumen of the external jugular vein during inspiration, leading to air embolism that may subsequently cause death.
• The external jugular vein is used by clinicians to measure the external jugular venous pressure and/or pressure in the right atrium.