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
Here Is What Is some of the tracks ("Beauty" and "Chest of Drawers") are conversations with Brian Eno. All songs written by Daniel Lanois unless otherwise noted. "Where Will I Be" is a new version of a song which had been previously released on Emmylou Harris' album "Wrecking Ball" in 1995. "Lovechild" and "Sacred And Secular" tracks incorporates, respectively, the pedal steel guitar melody used in "Carla", on Belladonna album, and the pedal steel guitar melody used in "Transmitter", on Shine album. Here Is What Is Here Is What Is is the fifth studio album by Canadian songwriter and record producer Daniel Lanois. It