REFLEX RESPONSES OF THE NICTITATING MEMBRANE

Abstract

Reflex contractions and relaxations of the smooth muscle in the nictitating membrane of the cat are described. The vagus is a suitable afferent to demonstrate reflex relaxation. Section of the vagi and denervation of the carotids increase the contractions elicited from the sciatic. Excitatory and inhibitory rebounds may be recorded. After-discharge may be very prolonged. Simultaneous stimulation of 2 afferents leads to summation of the reflex effects. The responses of the nictitating membrane are direct and not secondary to changes of blood pressure.