Carotid sinus

In human anatomy, the carotid sinus (or carotid bulb) is a dilated area at the base of the internal carotid just superior to the bifurcation of the common carotid at the level of the superior border of thyroid cartilage. The carotid sinus is sensitive to pressure changes in the arterial blood at this level. It is the major baroreception site in humans and most mammals.