Severe injury to skeletal muscle can be significant enough to raise CK-MB levels above normal, but such injury doesnât usually cause a high relative index. If your doctor suspects injury to both heart muscle and skeletal muscle, troponin is a more accurate test for identifying a heart attack.
The radial smooth muscle layer (dilator pupillae) is responsible for dilating the pupil. Source(s): http://en.wikipedia.org/wiki/Iris_%28ana...http://en.wikipedia.org/wiki/Dilator_pup...LaughingMan Â· 8 years ago.he iris is composed of two smooth muscle layers, arranged radially and circularly.
Light enters the eye through the pupil, and the iris regulates the amount of light by controlling the size of the pupil. The iris contains two groups of smooth muscles; a circular group called the sphincter pupillae, and a radial group called the dilator pupillae.