Mydriasis iris sphincter, composed of circularly arranged muscle fibers, and the iris dilator, composed of radially arranged muscle fibers. The sphincter is innervated by (signaled by nerves of) the parasympathetic nervous system, and the dilator by the sympathetic nervous system. Sympathetic stimulation of the adrenergic receptors causes the contraction of the radial muscle and subsequent dilation of the pupil. Conversely, parasympathetic stimulation causes contraction of the circular muscle and constriction of the pupil. The mechanism of mydriasis depends on the agent being used. It usually involves either a disruption of the parasympathetic nerve supply to the eye (which normally constricts the
Net-widening effect Net-widening effect A net-widening effect is when administrative or practical changes result in a greater number of individuals being controlled by the criminal justice system. Many policies and practices makes it easier for the government to expand the scope of its ability to catch and punish those who have committed crimes or are deemed to be at high risk of committing crimes. An example would be how probation and drug courts often serve to throw people in jail for non-criminal, technical violations of the conditions that were imposed upon them, at a higher rate than would be the case if