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
In the Light of What We Know In the Light of What We Know In the Light of What We Know is the debut novel of Zia Haider Rahman. First published by Farrar, Straus and Giroux, the novel was released in the spring of 2014 to international critical acclaim and earned its author the James Tait Black Memorial Prize, Britain's oldest literary prize. and the inaugural International Ranald McDonald prize 2016. The novel has already been translated into Dutch, French and Portuguese and is to be translated into several other languages. Much of the novel is set during the war in Afghanistan at the beginning of the