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
What Is a Rumpletilskin? What Is a Rumpletilskin? What Is a Rumpletilskin? is the first and only album by hip hop group Rumpletilskinz, released on July 13, 1993, on RCA Records and produced by the group's producer, R.P.M. The album failed to make it to any of the "Billboard" charts, but two singles did, "Attitudes" and "Is It All Right?" Both made it to #24 on the Hot Rap Singles. This release received extensive national independent retail promotion through Poindexter International Marketing & Promotions, which was employed by RCA Records. It was also one of the first projects managed by James "DJ Ras J"