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
Muscle car designed 2009 Camaro, which bears some resemblance to the 1969 model. The blend between old and new has fueled the muscle car revival. The mid-1960s muscle car era came to define what baby-boom men would expect from their automobiles. While the aging baby boom generation inspired the modern demand for classic-type American Muscle cars, the consumer market is much more diverse than it was in the 1960s and 1970s. Looking at modern muscle as a social trend, Ford and GM are the "innovators," followed by baby boom males in their 50s as "early adopters." The big bulge or "early majority"