Iris sphincter muscle Iris sphincter muscle The iris sphincter muscle (pupillary sphincter, pupillary constrictor, circular muscle of iris, circular fibers) is a muscle in the part of the eye called the iris. It encircles the pupil of the iris, appropriate to its function as a constrictor of the pupil. It is found in vertebrates and some cephalopods. Initially, all the myocytes are of the smooth muscle type but, later in life, most cells are of the striated muscle type. Its dimensions are about 0.75 mm wide by 0.15 mm thick. In humans, it functions to constrict the pupil in bright light (pupillary light
Muscle Shoals (film) Muscle Shoals (film) Muscle Shoals is a 2013 documentary film about FAME Studios and Muscle Shoals Sound Studio in Muscle Shoals, Alabama. The film was released by Magnolia Pictures on September 27, 2013. "Muscle Shoals" has generally received positive reviews from critics. Katie Van Syckle of "Rolling Stone" remarked "But the documentary’s real highlights are the musings of the musicians who recorded there. Performers including Aretha Franklin, Keith Richards, Mick Jagger, Jimmy Cliff, Ed King and Steve Winwood reflect on what went into creating the magical environment and the legendary recordings that it spawned. Artists were not only prolific in