Anatomy, Head and Neck: Carotid Sinus

Excerpt

The carotid sinus, also known as the carotid bulb, is a neurovascular structure that appears as a dilation at the bifurcation of the common carotid artery, and the beginning of the internal carotid artery. It is localized near the arterial pulse, inferior to the angle of the mandible at the level of the thyroid cartilage. The carotid sinus contains baroreceptors (stretch receptors), which are sensitive to pressure changes in the arterial blood pressure. The carotid sinus has dense innervation of many types of receptors that play a role in the control of blood pressure. Carotid sinus baroreceptor has a crucial role in the control of blood pressure and heart rate. Afferent signals travel from carotid baroreceptors to the cardiovascular control center in midbrain via the glossopharyngeal nerve. The efferent signals transmit via parasympathetic and sympathetic nerves to the heart and blood vessels. This response brings appropriate changes to maintain heart rate and blood pressure in normal physiological limits, which is known as carotid sinus baroreflex. There is inter and intra-individual variation in the location of the carotid sinus, which is clinically very important.