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 She Is (Is a Woman in Love) Hot Country Singles for the week of March 12, 1988. What She Is (Is a Woman in Love) "What She Is (Is a Woman in Love)" is a song written by Bob McDill and Paul Harrison and recorded by American country music artist Earl Thomas Conley. It was released in February 1988 as the lead single from the album, "The Heart of It All". The song was Earl Thomas Conley's fifteenth number one on the country chart. The single went to number one for one week and spent a total of thirteen weeks on the country chart. "What She Is