Carotid sinus reflex

The Karotissinusreflex ( Hering reflex, by Heinrich Ewald Hering, and not to be confused with the Hering-Breuer reflex) is a protective mechanism of the body to stabilize the central blood pressure and thus to secure the circulation of heart and brain.

Baroreceptors are located at the bifurcation of the carotid artery in the carotid sinus ( carotid sinus ), which measure blood pressure. An increase in blood pressure leads to irritation of these receptors, which is transmitted via the ramus sinus carotici of the glossopharyngeal nerve ( cranial nerve IX ) for circulatory regulation center in the medulla oblongata. About the efferent limb of the reflex cardiac branches of the vagus nerve ( cranial nerve X ), heart rate and blood pressure are lowered reflex.

When carotid sinus syndrome of pathological reflex is amplified and, in certain situations (such as when shaving or while wearing a very tight collar ) cause a transient cardiac arrest or a very sharp drop in blood pressure with the following syncope. By applying pressure to the carotid bifurcation ( Karotissinusdruckversuch ) of the reflex can be triggered artificially, and the subsequent reaction cycle are examined. In this way, supraventricular tachycardias can be terminated occasionally.