ABSTRACT
El reflejo barorreceptor es poco conocido por la mayoría de los médicos a pesar de que es fundamental en la estabilización de la presión arterial latido a latido y es crucial para la supervivencia. Su fascinante historia es brevemente revisada en este artículo. En 1852 Claude Bernard descubrió que los nervios simpáticos del cuello inervan los vasos sanguíneos de la piel. En 1932 Edgar Douglas Adrian demostró que los nervios simpáticos que inervan los vasos sanguíneos de la piel descargan en forma espontánea a una frecuencia de cuatro a seis por segundo y de esta forma encontró las bases fisiológicas del tono vasomotor. En el siglo XIX Ludwig Traube y Karl Constantine Ewald Hering descubrieron que la presión arterial fluctúa sincrónicamente con la respiración y Sigmund Mayer observó que también existían oscilaciones más lentas no relacionadas con la respiración. En 1921 Heinrich Ewald Hering mostró la existencia de barorreceptores de alta presión en los senos carotideos y probó que la estimulación de los nervios aferentes que inervan estos receptores induce bradicardia e hipotensión. Estos estudios fueron más tarde avanzados por Corneille Heymans quien ganó el premio Nobel por estos estudios en 1938. En la época de los setentas Cowley y Guyton produjeron denervación sino-aórtica en los perros y de esta manera demostraron la importancia fundamental del reflejo barorreceptor en la estabilización de la presión arterial.
The baroreceptor reflex is poorly known by most physicians even though is fundamental in stabilizing the blood pressure on a beat to beat basis and is crucial for survival. Its fascinating history is briefy reviewed in this article. In 1852 Claude Bernard discovered that the sympathetic nerves of the neck innervate the blood vessels of the skin of the rabbit. Edgar Douglas Adrian in 1932 demonstrated that the sympathetic nerves that innervate the blood vessels discharge spontaneously at a rate of 4-6 per second and thus discovered the physiological basis of the vasomotor tone. In the XIX century Ludwig Traube and Karl Constantine Ewald Hering discovered that blood pressure fluctuates synchronously with respiratory movements and Sigmund Mayer observed that there are also slow non respiratory fluctuations of blood pressure. In 1921 Heinrich Ewald Hering found that high pressure baroreceptors are located in the carotid sinuses and demonstrated that the stimulation of the afferent nerve that innervates it induces bradycardia and hypotension. These studies were further advanced by Corneille Heymans who won the Nobel Prize for these studies in 1938. Later Cowley and Guyton produced sino-aortic denervation in dogs and thereby could demonstrate the fundamental importance of the baroreceptor reflex in the stabilization of blood pressure.
Subject(s)
History, 19th Century , History, 20th Century , History, 21st Century , Humans , Baroreflex , Cardiology/history , Neurology/history , Physiology/history , France , United StatesABSTRACT
In the XIX century Claude Bernard discovered the action of the nervous system on the peripheral circulation. In the first half of the XX century Ewald Hering discovered the baro-receptor and the reflex control of the heart rate and blood pressure. Cowley and Guyton demonstrated that sino-aortic denervation induces persistent changes in the blood pressure in the dog. The autonomic nervous system is mainly responsible for the regulation of the circulation and blood pressure in the short term on a beat to beat basis. It controls the vasomotor tone, the heart rate and the cardiac output. With the advent of non invasive methods that measure the blood pressure on a beat to beat basis (Finapres) and with the methods of measurement of the variability of the blood pressure in the frequency domain (spectral analysis) we can currently measure many variables including heart rate, blood pressure, stroke volume, peripheral resistances and the baroreceptor sensitivity and make some inferences about their control mechanisms. These variables can be measured at rest in the supine position, standing up, during rhythmic breathing and during the Valsalva maneuver. In this article we present a review of the neural control of the blood pressure and heart rate.