Hering Reflex

HERING REFLEX (N. Hering), is characterized by a slowing of the pulse and a fall in blood pressure upon compression of the larynx. At a reduced ambient temperature, the reflex does not change; at an elevated temperature, there occurs an acceleration of respiration, an increase in blood acidity, and the H. r. disappears. Richet and Santenoise verified this reflex in animals and confirmed its existence. In their opinion, it is analogous in its action to the Aschner phenomenon. Hering also obtained a slowing of the pulse and a fall in blood pressure upon irritation of the sinus caroticus at the point where the arteria carotis interna originates ("sinus reflex"); the section of the first branch, which arises from the n. glosso-pharyngeus, eliminates the slowing of the pulse and the fall in blood pressure; irritation of its central end causes the same phenomena as direct irritation of the sinus caroticus.