although the openings of the veins do narrow during contraction. This retrograde movement of blood back into the veins may be observed as a pulse in the jugular vein of a normal person who is lying with the head and chest elevated about 30°. (Look in the hollow formed where the sternocleidomastoid muscle runs under the clavicle.) An observable jugular pulse higher on the neck of a person sitting upright is a sign that pressure in the right atrium is higher than normal.