Carotid sinus reflex

The carotid sinus reflex (also Hering reflex , according to 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 ensure the blood flow to the heart and brain.

At the bifurcation of the carotid artery , in the enlarged initial section of the internal carotid artery , the carotid sinus (carotid sinus ), there are baroreceptors in the vessel wall that measure blood pressure. An increase in blood pressure leads to the irritation of these receptors, whose signals are transmitted via the carotid sinus branch ( Ramus sinus carotici ) of the nervus glossopharyngeus (IX cranial nerve ) to the circulatory regulation center in the medulla oblongata . The heart rate and blood pressure are reflexively lowered via the efferent limb of the reflex , the cardiac branches ( rami cardiaci ) of the vagus nerve (Xth cranial nerve) .

In carotid sinus syndrome , the reflex is pathologically increased and in certain situations (e.g. when shaving or when wearing a very tight collar) it can lead to a temporary cardiac arrest or a very sharp drop in blood pressure with subsequent syncope . The reflex can be triggered artificially by applying pressure to the carotid fork ; this is carried out in the carotid sinus pressure test and the subsequent circulatory reaction is examined. Occasionally, supraventricular tachycardias can also be terminated in this way .

See also

• knockout

literature

• H. Volkmann: Carotid Sinus Syndrome . In: Hans-Holger Ebert et al .: The Syncope Pilot . Georg Thieme, Stuttgart 2009, ISBN 9783131556110 , p. 134.

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !