The anterior jugular vein is a blood vessel that is situated in the front of the neck. As it returns blood from the head to the heart, it receives blood from several smaller vessels in the face and in turn drains into the larger external jugular vein. A paired vessel, it runs vertically down either side of the anterior neck, with a small horizontal vessel known as the venous jugular arch linking its inferior or bottom ends. The anterior jugular vein carries blood that has been depleted of oxygen by the tissues in the face and neck and that has picked up carbon dioxide for elimination from the body back to the heart, where it will be sent to the lungs to receive oxygen once again.
As a vessel of the cardiovascular system, the anterior jugular vein is a small part of a network of vessels bringing deoxygenated blood back to the heart. Originating on the underside of the chin just to the front of the hyoid bone, the U-shaped bone of the neck felt immediately beneath the mandible or jawbone, the anterior jugular forms behind the chin to either side of the midline of the jawbone. It is fed by minor veins from the face, such as a small communicating division of the common facial vein, as well as by a few small laryngeal veins as it passes the larynx, or voice box.
Running in two parallel lines down the front central portion of the neck, the anterior jugular vein aligns vertically with either end of the clavicle or collarbone just above the sternum or breastbone. This is also where the innermost margin of the sternocleidomastoid, a long, narrow muscle running obliquely down the front of the neck from beneath either ear, attaches to the clavicle. Instead of reaching the clavicle, however, the paired anterior jugular vein ends an inch or so above the collarbone, its lower ends converging in an inverted-U shaped trunk known as the venous jugular arch.
After collecting several additional tributaries from the inferior thyroid veins, the venous jugular arch puts out vessels that drain blood from the anterior jugular vein into the external jugular vein. The external jugular is a larger vessel running down either side of the neck that collects most of the blood exiting the head. It carries this blood down to the superior vena cava, the large vein responsible for depositing deoxygenated blood from the upper body directly back into the heart.