Figure 5

Schematic illustration of the main effects of aspiration, expiration andcough reflexes in cats. Compared to normal values, the sniff-likeaspiration reflex (AspR), provoked by nasopharyngeal stimulationand characterized by rapid and strong gasp-like inspiratory flow (V’),manifests with distension of the chest and dilation of the cardiac cavities.This causes a decrease in the systolic volume (SV), due to retention of theblood in the heart. There is also a very strong activation of the sympatheticnerve (Sy), causing an increase in the blood pressure (BP) and a decrease invagal activity (nX). On the contrary, the expiration reflex (ExpR),characterized by rapid and strong expiratory effort, manifesting with chestcompression, which increases the next SV and BP and has a strong vagotoniceffect. The cough reflex (CR) has even stronger effects than the ExpR,due to its deep inspiratory phase, adequately strengthening the successiveexpiratory effort. In addition, the preparatory initial inspiratory phase ofcough is accompanied by a sympathetic activation, resulting in an increase inBP. Combined from results of our earlier publications [18, 22, 31, 40].