Iris dilator muscle Iris dilator muscle The iris dilator muscle (pupil dilator muscle, pupillary dilator, radial muscle of iris, radiating fibers), is a smooth muscle of the eye, running radially in the iris and therefore fit as a dilator. The pupillary dilator consists of a spokelike arrangement of modified contractile cells called myoepithelial cells. These cells are stimulated by the sympathetic nervous system. When stimulated, the cells contract, widening the pupil and allowing for more light to pass through the eye. It is innervated by the sympathetic system, which acts by releasing noradrenaline, which acts on α1-receptors. Thus, when presented with a threatening
What Is to Be Done? (novel) Is to Be Done?" is one of the sources of inspiration for Rand's thought. For example, the book's main character Lopuhov says "I am not a man to make sacrifices. And indeed there are no such things. One acts in the way that one finds most pleasant." Vladimir Nabokov's final novel in Russian, "The Gift", ridicules "What is to Be Done?" in its fourth chapter. What Is to Be Done? (novel) What Is To Be Done? (; also translated as What Shall We Do? and literally translated as "What To Do?") is an 1863 novel written by the Russian philosopher,