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 Beach the original Santa Monica site. The contemporary Muscle Beach Venice is located two blocks north of Venice Boulevard on Ocean Front Walk in Venice, California. Santa Monica's "Muscle Beach" landmark derives its name from the growing local and national reputation of gymnastics and strength athletes who congregated at what was first known simply as the "Santa Monica Beach Playground", with the 'muscle' term gaining momentum by 1940. The 1940 opening of the first of an eventual nationwide chain of weightlifting gyms by famed pioneer gym chain operator, Vic Tanny, only two city blocks from Muscle Beach in Santa Monica, is