71). THE CAROTID SINUS

[Editor]

a) is most sensitive to changes in systemic pressure
b) has increased activity when blood pressure falls
c) afferent fibres are carried in the glossopharyngeal nerve
d) are chemoreceptors
e) sense changes in carbon dioxide tension

[Editor]

tftff

The carotid sinus-baroreceptors in the dilatation of the internal carotid artery, just above the carotid bifurcation. They respond to increased distension caused by raised arterial BP by increasing the rate of discharge via the carotid sinus nerve, a branch of the glossopharyngeal nerve. If stretch decreases baroreceptor output frequency decreases. Baroreceptors not only respond to pressure magnitude, but also rate of change of pressure, The impulse discharge rate is therefore greater during early systole than diastole.